[iOS17] Phone won't ring anymore - "User Busy"

Apologies if this isn't the best place to post this...

I'm not able to receive phone calls anymore after updating to iOS17. My friend told me that they tried calling me 4 times and got a busy signal every time. I told them that my phone never rang (which is true) but, when I went to my missed calls, it shows 4 missed calls from them. I asked them to call me again (while I was looking at my phone) and the notification banner for the call comes in for a split second but is "greyed out" and says their name and then "User busy" before disappearing.

I've restarted my phone, checked to make sure I didn't accidentally block them, added them to my Favorites, and even had someone else try to call me and all result in the same thing. My computer rings via FaceTime when some people call me but it seems like my phone won't ring at all and everyone just gets a busy signal.

Any ideas? Anyone else getting this after the update? I've searched for a while now but every reference to "User busy" is old and just says something to the effect of "restart your phone" or "change your settings to allow unknown/junk callers". This isn't either of those things, though.