Fedora dnf keepcache not working?

I coming from 1911753 – dnf history undo not working and later I found on other BZ link mentioned to add keepcache=1 on my /etc/dnf/dnf.conf
So I added and give a try

$ sudo dnf update --refresh
Fedora 33 openh264 (From Cisco) - x86_64                                                                                                                        555  B/s | 989  B     00:01
Fedora 33 - x86_64 - Updates                                                                                                                                    6.6 kB/s | 6.9 kB     00:01
determining the fastest mirror (1 hosts).. done.                                 [                                    ===                                     ] ---  B/s |   0  B     --:-- ETA
Fedora 33 - x86_64                                                                                                                                              4.0 kB/s | 6.7 kB     00:01
Dependencies resolved.
================================================================================================================================================================================================
 Package                                                  Architecture                         Version                                              Repository                             Size
================================================================================================================================================================================================
Upgrading:
 libreswan                                                x86_64                               4.2-0.1.rc1.fc33                                     updates                               1.1 M
 perl-Module-CoreList                                     noarch                               1:5.20201220-1.fc33                                  updates                                82 k
 perl-Module-CoreList-tools                               noarch                               1:5.20201220-1.fc33                                  updates                                19 k

Transaction Summary
================================================================================================================================================================================================
Upgrade  3 Packages

Total download size: 1.2 M
Is this ok [y/N]: y
Downloading Packages:
(1/3): perl-Module-CoreList-tools-5.20201120-1.fc33_5.20201220-1.fc33.noarch.drpm                                                                                27 kB/s |  11 kB     00:00
(2/3): perl-Module-CoreList-5.20201120-1.fc33_5.20201220-1.fc33.noarch.drpm                                                                                      36 kB/s |  15 kB     00:00
/var/cache/dnf/updates-0e22a1f5a0a34771/packages/perl-Module-CoreList-tools-5.20201120-1.fc33_5.20201220-1.fc33.noarch.drpm: md5 mismatch of result           ] 905 kB/s | 122 kB     00:01 ETA
(3/3): libreswan-4.2-0.1.rc1.fc33.x86_64.rpm                                                                                                                    1.1 MB/s | 1.1 MB     00:01
/var/cache/dnf/updates-0e22a1f5a0a34771/packages/perl-Module-CoreList-5.20201120-1.fc33_5.20201220-1.fc33.noarch.drpm: md5 mismatch of result
Some packages were not downloaded. Retrying.
(1/2): perl-Module-CoreList-tools-5.20201220-1.fc33.noarch.rpm                                                                                                   77 kB/s |  19 kB     00:00
(2/2): perl-Module-CoreList-5.20201220-1.fc33.noarch.rpm                                                                                                        251 kB/s |  82 kB     00:00
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total                                                                                                                                                           408 kB/s | 1.3 MB     00:03
Failed Delta RPMs increased 1.2 MB of updates to 1.3 MB (-2.1% wasted)
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                                                                                                                        1/1
  Running scriptlet: perl-Module-CoreList-1:5.20201220-1.fc33.noarch                                                                                                                        1/1
  Upgrading        : perl-Module-CoreList-1:5.20201220-1.fc33.noarch                                                                                                                        1/6
  Upgrading        : perl-Module-CoreList-tools-1:5.20201220-1.fc33.noarch                                                                                                                  2/6
  Upgrading        : libreswan-4.2-0.1.rc1.fc33.x86_64                                                                                                                                      3/6
  Running scriptlet: libreswan-4.2-0.1.rc1.fc33.x86_64                                                                                                                                      3/6
  Cleanup          : perl-Module-CoreList-tools-1:5.20201120-1.fc33.noarch                                                                                                                  4/6
  Cleanup          : perl-Module-CoreList-1:5.20201120-1.fc33.noarch                                                                                                                        5/6
  Running scriptlet: libreswan-4.1-3.fc33.x86_64                                                                                                                                            6/6
  Cleanup          : libreswan-4.1-3.fc33.x86_64                                                                                                                                            6/6
  Running scriptlet: libreswan-4.1-3.fc33.x86_64                                                                                                                                            6/6
  Verifying        : libreswan-4.2-0.1.rc1.fc33.x86_64                                                                                                                                      1/6
  Verifying        : libreswan-4.1-3.fc33.x86_64                                                                                                                                            2/6
  Verifying        : perl-Module-CoreList-1:5.20201220-1.fc33.noarch                                                                                                                        3/6
  Verifying        : perl-Module-CoreList-1:5.20201120-1.fc33.noarch                                                                                                                        4/6
  Verifying        : perl-Module-CoreList-tools-1:5.20201220-1.fc33.noarch                                                                                                                  5/6
  Verifying        : perl-Module-CoreList-tools-1:5.20201120-1.fc33.noarch                                                                                                                  6/6

Upgraded:
  libreswan-4.2-0.1.rc1.fc33.x86_64                   perl-Module-CoreList-1:5.20201220-1.fc33.noarch                   perl-Module-CoreList-tools-1:5.20201220-1.fc33.noarch

Complete!

So let see…

$ sudo dnf history info last
[sudo] password for robbi:
Transaction ID : 16
Begin time     : Thu 31 Dec 2020 10:50:22 AM +08
Begin rpmdb    : 1448:46959b33ef3c9604fe74ec6a98b5d13771f73f3b
End time       : Thu 31 Dec 2020 10:50:28 AM +08 (6 seconds)
End rpmdb      : 1448:2ae6f413e5cbe0a6650c5a4d848b6ab6bc1d536d
User           : robbi <robbi>
Return-Code    : Success
Releasever     : 33
Command Line   : update --refresh
Comment        :
Packages Altered:
    Upgrade  libreswan-4.2-0.1.rc1.fc33.x86_64                     @updates
    Upgraded libreswan-4.1-3.fc33.x86_64                           @@System
    Upgrade  perl-Module-CoreList-1:5.20201220-1.fc33.noarch       @updates
    Upgraded perl-Module-CoreList-1:5.20201120-1.fc33.noarch       @@System
    Upgrade  perl-Module-CoreList-tools-1:5.20201220-1.fc33.noarch @updates
    Upgraded perl-Module-CoreList-tools-1:5.20201120-1.fc33.noarch @@System

Now I want to undo and expecting dnf save my previous version and my downgrade should be successful…but…

$ sudo dnf history undo last
Last metadata expiration check: 0:16:46 ago on Thu 31 Dec 2020 10:49:59 AM +08.
Undoing transaction 16, from Thu 31 Dec 2020 10:50:22 AM +08
    Upgrade  libreswan-4.2-0.1.rc1.fc33.x86_64                     @updates
    Upgraded libreswan-4.1-3.fc33.x86_64                           @@System
    Upgrade  perl-Module-CoreList-1:5.20201220-1.fc33.noarch       @updates
    Upgraded perl-Module-CoreList-1:5.20201120-1.fc33.noarch       @@System
    Upgrade  perl-Module-CoreList-tools-1:5.20201220-1.fc33.noarch @updates
    Upgraded perl-Module-CoreList-tools-1:5.20201120-1.fc33.noarch @@System
No package libreswan-4.1-3.fc33.x86_64 available.
No package perl-Module-CoreList-tools-1:5.20201120-1.fc33.noarch available.
No package perl-Module-CoreList-1:5.20201120-1.fc33.noarch available.
Error: no package matched

hmmm…