iOS 11 freezes, and music bug

Hi, since upgrading to iOS 11 have these two issues:

1

Occasionally the screen becomes unresponsive - freezing at current frame and not responsive to my touch, the home button, volume buttons, power button, etc. It stays on the frame for maybe 20 seconds, then unfreezes and becomes very sluggish, barely responding to touch and still not responding to the buttons. Then it freezes at current frame again. Maybe after 5 minutes the phone goes black and shows a loading icon (no apple logo), then loads the lock screen, after which it’s okay again. But the freezes seem to happen at seemingly random times and potentially when I’m doing something important.

2

The music app, when open, often doesn’t display correctly in the control center or lock screen and is not manageable from there, instead just showing the default blank album art with back/forward/play buttons that don’t respond when tapped, meaning that to change the song or see what’s playing I have to unlock the phone and reenter the music app to do so.