So I assume the first order is to add the tde r14 repo's to the apt sources lists. Can you supply that repo line please?
If it works for you, I would suggest a clean bookworm installation without other DEs and then add TDE. You can find the TDE installation instructions here: https://wiki.trinitydesktop.org/Debian_Trinity_Repository_Installation_Instr...
Thanks Michele, take care and stay well.
Thanks, you too!
Cheers Michele