Composing text Diappears

so Frustrating that my text I am I. The middle of composing vanishes even if O got into multitasking, maybe to switch to grab a synonym of a word frim an app or browser. Go back to message and it’s gone. Or set phone down it goes to sleep wake it, message is gone.

I mean come on???? I spend this much for a phone and it can’t multi task?