XR Ring App - "Invalid Credentials"

Several days ago now I was away from home & rec'd motion hits on my doorbell via the Ring App on my IPhone. When I tried to check the activity I rec'd a "could not connect to server" message. Looked again when I got home & I couldn't even sign in on my Ring app. Tried turning phone off/on, deleting/reinstalling the app, nothing worked. Tried to change password & rec'd "Invalid Credentials" for my email address too. Ring app works great on wife's IPhone, same user, same PW; works gerat on Ipad & computer, same account. Contacted Ring Support & they gave me a patient 1.5 hours but nothing worked. AT&T Support spent nearly 2 hours with me, tried all steps same as with Ring Support, finally did a complete factory reset & still "Invalid Credentials". AT&T Support concluded that something in the Ring App was blocking the IMEI assigned to my phone. I did reach back out to Ring Support via email but no response. Still at a loss so reaching out to community for guidance. Something that might apply: I had to disable NordVPN on my computer before I could post on this site .................