The other day I thought it was strange when I pressed the volume button on my Samsung S8 (Android 7.0) and the in-call volume slider popped up. It was strange because I wasn't in the middle of a phone call at the time. For some reason my phone now frequently thinks I'm on a phone call when I'm not.
This is particularly bad because it causes notifications to be muted. Restarting the phone only temporarily fixes the issue.
I didn't have this problem when I got the phone (from AT&T) about 2 weeks ago. And I've only added 4 additional apps to my phone--BitDefender Antivirus, Gboard, the ESPN app, and a messaging application called PerfectServe. Disabling all 4 apps doesn't fix the problem. Is this a Samsung issue?