iMac won’t access internet with iPhone hotspot

At this time I don’t have Wi-Fi, my provider is down. So I tried to connect my iMac 21.5” (2019) to my iPhone 12 Pro Max hotspot, and while it shows it’s connected I still can’t access the Internet. In the past, my last iPhone was able to connect to this iMac and get on the Internet. My phone is OK, because my iPad will connect to my phones hotspot. So the problem is with the iMac.

Apple agents have tried to help me but with no success, maybe someone else has had this problem.