Why does my phone hang up immediately upon connection?

[Android Central Question]

I have a Galaxy S7 Edge. Starting today, my phone immediately hangs up whe I answer an incoming call, or hangs up immediately when a call I make is answered. I have tried several fixes that I've seen on the wed, such as "reset network settings", enable and then disable wi-fi calling, rebooting, etc. I also uninstalled WhatsApp, since that app was used in the last call I received today. Nothing works and I cannot make any calls.

 

[garytvh]

I am the person who added the above question. I forgot to mention that I tried rebooting in safe mode and was able to make and receive calls. However, no apps have been added in the recent past - at least one month. Other web searches say that if you can make calls in Safe mode, but not in regular mode, then the problem is a bad app and not hardware. I don't know what to try next.

 

[garytvh]

Problem resolved, I think. After I put the phone in safe mode I made and received calls to make sure that this was working, and it did in Safe mode. I then ran Verizon's Security and Privacy app and did a scan - no issues found. I then rebooted the device and amazingly it now works!!!/ I wondering if putting it onto safe mode, exercising it there, and then rebooting cleared the problem??? Whatever, it now works.