Suddenly getting "To enable personal hotspot, contact your carrier" message in settings

I worked for Verizon data provisioning for six years, so I know what that means. I will also note that this account has two numbers associated with it, mine and my brother in law. He still has personal hotspot available on his phone while I do not. The telecom agent said she compared the two accounts side-by side and there is no difference in the settings. I know that rare software glitches can happen that don't always show up in telecom GUIs, but there isn't even an option to turn on/off tethering for my account because it is an unlimited data plan. Only plans that are voice + limited data access come with a tether/no tether option.

My brother in law is traveling at the moment, but when he returns I am going to swap the SIMs between his phone and mine to see if the problem stays with the phone or the account. Will update this thread with the findings.

"Escalate the call until you get someone who knows what that means." is not going to be a simple 5-minute phone call.

But as promised, I have an update. Last night I swapped the SIM cards with my brother's phone and initially the problem stayed with my phone, even with his SIM card in it. My phone (with his SIM in it) still showed "contact carrier to enable hotspot", while his phone (with my SIM in it), had a working hotspot option.

This strongly suggests the problem is with the phone, not with the SIM/account.

However when I swapped them back, the hotspot was enabled again on my phone with my SIM inside. It's pretty clear the phone was the issue here. Maybe not making good contact with the SIM? Who knows. If it happens again I won't even try to swap SIMs, I'll just pull it out and put it back in again to see if that clears up the problem.

Just popping back in to report that this happened to me again yesterday. I had been using the hotspot in the morning, then tried to use it again in the early afternoon when I suddenly got the message to contact my carrier to enable tethering.

My brother was here and I immediately swapped our SIM cards. My SIM worked fine in his phone and I could set up tethering. I tried to power cycle my phone and then was getting ready to do a wipe/restore but when I connected to iTunes to do a backup first, I got a message that an iOS update was available for the phone. So I did that first and the issue was resolved.

Power-cycle = shut down the phone cold and turn it back on.

Regarding iOS update, I don't usually go looking for it. But when I connected to the PC to back up the phone, I got a pop-up from iTunes that an iOS update was available. So I did that first and after the update the personal hotspot option was available once again.