Find in which group the package was installed

$ dnf repoquery --installed --qf='%{name}-%{evr}.%{arch} (%{reason})'
grub2-pc-1:2.06-109.fc39.x86_64 (group)

$ dnf repoquery --groupmember grub2-pc

When using repoquery grub2-pc is listed as group install, but I have neither group installed. (Default installation, and I tried recursively dnf group info on every installed group, but didn’t see the 2 groups.)
How to find the reason of the group mark?

Is grub stuff just manually marked as group without actually having a group, during install / image creation?
In F29 they were in --userinstalled, but no longer in later versions.

How did you install the system?

It’s a VPS that provided only Fedora 29 server image, the system is then upgraded to F39 with 5 upgrades.
Fedora 39 workstation on my PC is used as a reference for what the installed package list is supposed to be like. It’s installed using anaconda on live-usb (F39 fresh install) as usual. The command output is from the PC.