No one here can do anything about it.
Except maybe confirm or deny the behavior. If it works fine for everyone else, then the OP knows it's not a bug per se, but a fault with his system somewhere.
Read the post again. It works with non-nested media. That either means that the behavior with nested media is a) a bug or b) needs a feature request. Same form.
it is a bug to me, not a feature request. Because with that behaviour multicam edits with P2 material simply are not possible.
Could someone confirm this bug?