Calls sent straight to voicemail after iphone 15.1 update

JustAC wrote:

I have been looking at my phone when a call is made to my number and a call notification immediately pops up that I have a missed call but my phone is not ringing.

Verify your iPhone shows Network Coverage when that is happening and that you are able to make outgoing call right after.

If both are true - iPhone does have Network Coverage, and it can make outgoing calls, then talk to your Carrier why incoming calls to your number are routed directly to your voicemail and not to your iPhone.

I am having the same problem as described above ever since updating to 15.1 (started exactly when updating). Many calls ring once and then the caller receives my voicemail (I see the call and attempt to answer but cannot). Like the orig poster, focus is off, do not disturb is off, these callers are not blocked in anyway. It is random and regular callers (even ATT when when I called them and they called me back). My carrier settings are up to date as well. I have restarted my phone and have network coverage. This happens with and without Wifi on. With and without wifi calling enabled. Any ideas? It is indeed a 15.1 issue.

I had same problem with iPhone 12, even after updating to iOS 13. Mine solved by going to Settings, Phone, Calls on Other Devices. Mysteriously, the setting in place was to allow calls on another family member iPhone, which was under same wireless plan, when phone was nearby. I turned that off and problem (so far) fixed.

I am having the same problem using iPhone 8 Plus. Cannot find a fixe.

Having same problem with iPhone 11 Pro Max

How did you fix, I’m having the same problem

15.2 solved for me on 12 Pro Max.

15.2 solved for me on 12 Pro Max.

I have an iPhone 8+ and I just started having this problem today. I believe 15.2.1 was installed yesterday.

Correction to preceding: even after updating to iOS 15.3

15.2 solved for me on 12 Pro Max.