sorry for the necro but its rough to see that this still happens. i just finished
wiping out the grove only for the game to switch to shadowheart in the end convo with minthara
and now i gotta redo everything cuz of it. i get some of it is my fault for not saving often but when ur into it its tough to remember and the game's massively unreliable with auto save.

i understand switching char mid dialogue would be hard to implement but at least take a closer look at the post combat char select option cuz doesn't matter if its "avatar" the game will bug out at some point and switch to some random companion cuz F you go do this all over again. this has happened multiple times in all my 3 playthroughs