Have u tried uninstalling and reinstalling the game? Cuz a friend of mine was having the same problem and that fixed it for him, maybe the game is making use of old geometry in the files that wasn't cleaned up in the new patch
I mean its probably not a bug, but I think Rem has similar color palette as the Archmother, which makes it a lot difficult to see him, especially being a small character. You can see its even harder to see his skills which share similar color patern.
This prob because of the new assist system, like if hes some meters close to the kill he gets assist even tho he didn't actually did any dmg to the player. I really hope they find a better way to count assist as this makes farming stacks stupid. Hes a hunter supposed to risk hunting lone...