Anyone encountered issues with cellular?

My 11 pro max has no problem, using maxis physical SIM 4G smooth. But my wife’s 11 maxis eSIM and Umobile physical SIM both cannot connect. It’s either searching or EDGE. Certain location can get 4G but the internet barely moves. Accessing to google.com takes more than a minute.

Wife’s the principal line, both of us has tons of data left.

Already done reset network/restart phone etc. suspecting it could be antenna problem? But if it’s antenna then wouldn’t even be able to search network, right?

Funny how it works fine after a good night’s rest. Gonna have to monitor further.