Auto-Role Multiplier

I am attempting to give newly joined members a boost to their XP upon joining, which I'll remove after some time. I haven't seen this mentioned anywhere in the documentation, but it looks like every time I set the role as a multiplier, it removes it from autorole/join role, and vice versa. Is this intended behavior? It's rather frustrating, but if I missed something I'm sorry to waste your time. (A simple story in screenshot form, in which I have the multiplier role, add it to on-join, and then see that it is no longer in multiplier.)