I got news from @mvo: 2.55.3 with the fix for the bug of the CUPS_SERVER environment also set in the CUPS Snap and Snaps plugging cups-control is already released into the beta channel. @mvo will work on the bug of environment variables in Snaps persisting through restarts and updates in the beginning of next week.
@jovimaco, with snapd 2.55.3 installed LibreOffice should list your printers correctly and you should be able to print. Please test this by running the command:
sudo snap refresh --beta snapd
and then checking the print dialog of LibreOffice again. If you do not see your printers, run the command
sudo /usr/lib/snapd/snap-discard-ns libreoffice
Does it work correctly now?
If the problem occurs again for you, to get back into working state, do
sudo snap refresh --stable snapd
sudo /usr/lib/snapd/snap-discard-ns libreoffice
Please tell us your results. THanks.