iPhone SE problems on 11.0: apps freezing and voice call problems
You should backup your iPhone SE with iCloud backup.
Then restore it to factory by using iTunes on a computer (Mac or PC/Windows). This will erase the entire phone (hence why a backup is recommended 1st) then it will install iOS 11 with a fresh install. Not with layers of patches, which is what you currently have). After the restore is done, and the iPhone says hello, then you can set up the iPhone and then restore from iCloud backup. That should help with the software problems. 

As for the calling aspect, if it pops up again, remove and re-insert your SIM card tray into the iPhone (right hand side of the phone). If the issue persists afterwards, reset all settings.