Flatpaks no loger spawn from toolbox

I’ve been running flatpaks fine from toolbox (Emacs and Steam mostly) but all of a sudden I am getting this: bwrap: Can't find source path /run/user/1000/doc/by-app/com.valvesoftware.Steam: No such file or directory I know it has something to do with mount points and xdg-*, but I’m a little confused. Everything runs fine on host, but breaks in toolbox. I haven’t made any changes regarding the toolbox except for upgrades on the system and within the toolbox:
Toolbox upgrade:

    Upgrade  hwdata-0.341-1.fc33.noarch               @updates
    Upgraded hwdata-0.340-1.fc33.noarch               @@System
    Upgrade  libsmbclient-2:4.13.2-2.fc33.x86_64      @updates
    Upgraded libsmbclient-2:4.13.2-1.fc33.x86_64      @@System
    Upgrade  libwbclient-2:4.13.2-2.fc33.x86_64       @updates
    Upgraded libwbclient-2:4.13.2-1.fc33.x86_64       @@System
    Upgrade  samba-client-libs-2:4.13.2-2.fc33.x86_64 @updates
    Upgraded samba-client-libs-2:4.13.2-1.fc33.x86_64 @@System
    Upgrade  samba-common-2:4.13.2-2.fc33.noarch      @updates
    Upgraded samba-common-2:4.13.2-1.fc33.noarch      @@System
    Upgrade  samba-common-libs-2:4.13.2-2.fc33.x86_64 @updates
    Upgraded samba-common-libs-2:4.13.2-1.fc33.x86_64 @@System
    Upgrade  samba-libs-2:4.13.2-2.fc33.x86_64        @updates
    Upgraded samba-libs-2:4.13.2-1.fc33.x86_64        @@System
    Upgrade  wine-core-5.22-1.fc33.x86_64             @updates
    Upgraded wine-core-5.21-1.fc33.x86_64             @@System
    Upgrade  wine-filesystem-5.22-1.fc33.noarch       @updates
    Upgraded wine-filesystem-5.21-1.fc33.noarch       @@System

rpm-ostree upgrade:

  binutils 2.35-15.fc33
  binutils-gold 2.35-15.fc33
  buildah 1.18.0-1.fc33
  hwdata 0.341-1.fc33
  kernel 5.9.11-200.fc33
  kernel-core 5.9.11-200.fc33
  kernel-devel 5.9.11-200.fc33
  kernel-modules 5.9.11-200.fc33
  kernel-modules-extra 5.9.11-200.fc33
  libsmbclient 2:4.13.2-2.fc33
  libwbclient 2:4.13.2-2.fc33
  samba-client 2:4.13.2-2.fc33
  samba-client-libs 2:4.13.2-2.fc33
  samba-common 2:4.13.2-2.fc33
  samba-common-libs 2:4.13.2-2.fc33
  samba-libs 2:4.13.2-2.fc33

My only idea is maybe a bug in buildah, but on an rpm-ostree rollback I still get the same issue. There are threads here and there going over similar issues, but none of the solutions seem to apply to or work in the toolbox environment. Any help would be appreciated!

See Starting Flatpak applications fails from Toolbox · Issue #659 · containers/toolbox · GitHub

I am very surprised to know that it was actually possible to run Flatpaks from inside a Toolbox container. This seems to have been some happy coincidence because this isn’t supposed to work until we land the code for:

I doubt that Buildah is involved, because it doesn’t enter the picture on your client computer. It might be used on the Fedora infrastructure to generate the fedora-toolbox image, but I can’t see how that can affect this.