iMessage notifications iPhone X

I’m continuing to have multiple issues with the last 3 iPhone Xs. Initially I was having horrid battery performance, like 1-2 hours, got my 2nd iPhone X as apple demed it a hardware issue. 2nd iPhone X had also bad battery but was also not receiving iMessage notifications in lock screen, my group text message contact initial tags were flashing in a sporadic pattern, could not type a contact name into iMessage without it immediately deleting. Also, in my lock screen when I pulled down the notification screen I would see flashing notifications. Did a factory reset from new(not back up) and issues continued. Received 3rd iPhone X today after apple again demed it a hardware issue and guess what....all iMessage issues I just explained continue!!!!!! Somebody, anybody please offer suggestions. This is my last straw with Apple’s BS!