I literally went into Gmail app, settings then general settings and turned on all notification settings, then did the same with my Gmail account. Then went into the ultras notification settings and turned all of them on. So far I've received all notifications. One thing I did notice, I've got 2 android phones(the ultra, and ZTE AXON 10 pro), and a huawei tablet on Gmail. When I get a message, the ZTE and tablet get the message first and the ultra receives it about a minute later. I don't think it has anything to do with the devices as this happened when I had my LG phone instead of the ultra.