@Cosmoros: fixed!

viantdroom_event.txt, you forgot a closing bracket at the end.

@Dr. Quackers M.D., you can try my addon to this mod (Diverse Rooms fix all random), may be it will help in your case.

Just checked: this mod works as indended: rooms of AI empires are randomized (at least at start of a game and 200 years later). There are some cases there may emerge a default room for AI empires: these rooms are hardcoded at several dlc's scripts, and nor I, nor Diverse Rooms author alters these scripts as it breaks compatibility with many many mods. May be loadorder not correct? Place this mod after Diverse Rooms mod in loadorder.

random empires always choose the same room