I updated my Note 4 to Marshmallow this afternoon. So far, I've noticed the following issues hours after the update:
1. Advanced calling took forever to activate (about 7 hours), but finally did. WiFi calling seems to work, but the other party isn't very loud even with the volume all the way up.
2. My home screen is resetting after being customized. This has happened even after factory resets and battery pulls. My custom clock/weather widget gets replaced by the S Note and S Health Widget. So far, this has happened twice.
3. The third and most aggravating issue, my signal strength has dropped according to the meter. I've gone from 4 bars of service to 1 at my house. I'm also getting the 1X icon instead of 4G LTE. I've never had issues at my house before, so I don't know what's going on now.
Just wondering if anyone else is having issues after the update.