Yeah, steam mobile is a piece of stuff. I've had it freeze, crash, notify me that I have a message and then proceed to pretend it never existed, and, at one point, break so hard I had to reboot the phone. It also freezes whenever someone is typing a message to me in steam chat, but only when I'm not on wifi(how tf did you manage this valve)
Yeah it used to be fine, but several months ago they started pushing out updates that break something new.
I'll get notifications that don't open anything when the I tap them, I'll get messages and never get notifications until I open steam to message someone, or I'll get them an hour+ after I've already viewed and responded to the message. I've never had it freeze when someone is typing, it just repeatedly turns the user is typing "..." message on and off so the entire chat flickers up and down. And then when I get home and don't need it, I have to completely log off instead of just close the app, or I'll still get messages.