Not quite a bug, rather a defect. I create custom faction based on United Empire and also changed population politics and bonuses, so when i pick "staying united empire" in offer between sherydyn, vaulters or staying united empire, my custom population transform into common imperials with +1 influence, instead of remaining initially created. I think that is wrong. 

Sorry for my english.

Hello Greensmokie :)

Yes, it is a kind of defect, so we decide to fix it according to the community reports.

This issue should be fixed soon (probably next patch).

Quaedam.