I turned myself into a zombie villager, and then cured myself to become a villager, and when I get struck by lightning, it does turn me into a witch, but it banishes me from the witch instantly. I can't repossess it and I have all my inventory with me even as the ghost, except I can't scroll through my hot bar or move things around, but I think that part is normal. It's just the witch kicking me out that is weird.

I can't reproduce, does this happen with the latest version of Requiem ?

Well, if you can reproduce this on the latest version, feel free to reopen

Huh. Indeed, that sounds like a bug.