Here's a few tips that should be put up on the install instructions pages that might help others while transitioning to Docker or Podman.
I was struggling as I had most of my BOINC's running on Linux boxes on flatpak, couple on Windows. On Windows I can't remember the hoops I had to just through before figuring it out but I'll try to go through again on the VM and try to replicate an post later.
Linux Mint and other ubuntu-debian types.
Remove/uninstall all boinc installs first, from distro,boinc site, and flatfpak/flathub etc.
These instructions should be
Install podman:

sudo apt install podman

sudo usermod -a -G boinc $USER

sudo usermod --add-subuids 100000-165535 --add-subgids 100000-165535 boinc

sudo usermod --add-subuids 100000-165535 --add-subgids 100000-165535 PUT_USERNAME_HERE

Reboot, check you user and group and make sure your user name is member of boinc group.
Then install BOINC from https://boinc.berkeley.edu/download.php for your distribution.

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Win11 x64-Asus AMD 2.7GHz-32GB-GT760
Garuda x64-Dell-i5-4.6GHz-32GB-GT1030
Mint 22.1-i5-3.7GHz-32GB-2xGT760
Mint 22.1-Xeon-2.6GHz-32GB-ecc-GT760