Bug report of Assimilation bug:

It's turn 35 and I have Andromeda minor civ under my control (completed the quest some turns ago). The status says converted. Diplonatic relation state is converted and I am their ally. I killed off all the Hissho's systems and now just waiting for them to fade into oblivion (next turn).
Currently working on taking out the Sophons.
Turn 36 is where the bug starts showing itself. Start of turn 36 it says I'm now the sovereign of Andromeda and the quest to assimilate is available (again!) even though I already had them converted. This bug also happens if you just brainwash them instead of completing the quest.
Turn 37 the bug is getting worse. It says nobody is Andromeda's ally even though they are converted. The quest to assimilate is still active.
Turn 38 the bug is still there. Now it says their ally is me again. What is going on?