Hey there!
I'm really happy that you brought Anno1800 to consoles!
Playing on the PS5 version, free trial.
Yesterday during playing the Campaign, I've encountered the following bug. I was unable to select anything from the "Actions" in the Diplomacy menu, selecting something from the "Treaties" worked just fine
I don't have permissions to upload a video, but I've uploaded a short video clip here: https://file.io/SUliuIhjAPel
I went back to the main menu and created a fresh game in sandbox mode and tried it there as well, but I encountered the same bug!
The only thing that fixed it for me, was completely closing and opening the game.
I'm not the only one experiencing this bug and it is also present on the Xbox version. Furthermore, for some people restarting the game doesn't fix it.
(https://www.reddit.com/r/anno1800/comments/11v04na/ps5_unable_to_select_actions_left_in_diplomacy/)
Hope you can fix this, this was the only bug I've encountered so far and it is really a fantastic port!
EDIT: Just a quick update, I encountered the bug yesterday again, and restarting the game did not fix it this time... I really have no clue how I was able to fix it.