New 11- all calls go straight to VM

New phone- everything else works-no issues w/ texts (with notifying sound), making calls, FaceTime, cellular data- maps, browsing.

-All calls come in without any notification and go to VM. I am able to hear the messages.

I followed all Support troubleshooting- Do Not Disturb" is off, no calls are blocked, ringtone/volume all appropriately set. No call blocking software installed.

The one thing I was unable to do:

When I attempt to check “call forwarding” setting, I am unable - just circles and never opens the page. “Call waiting” opens but toggling prompts error message “could not save call waiting setting.”

Spent 40 minutes chatting with Apple - removed and replaced SIM - basically everything short of factory reset.

I was advised to contact my carrier (Boost (Sprint)) and obtain “ticket number,” then call Apple back and ask for “Senior Tech.”

Spent an additional 40 minutes with Boost Support - who had me re do almost every single trouble shooting step I’d already done. Boost Support then said he’d exhausted everything he could to and would have to escalate my call to “the highest priority” or some such. I was then transferred right back into the Boost Support queue where I waited for another 15 minutes before hanging up in disgust.

Can anybody out there tell me what is going on? Is it hardware, software, carrier???

Thanks!!!