Ok slight update. I've been using my work phone (iPhone) which roams to register and I had no luck. I decided to give it a shot on my personal phone (Google Pixel running Android 8.1). It doesn't matter which phone you use to login even if it's the same account as long as you punch in the verification SMS.

I entered my CSR card # and somehow it linked up in Android successfully. Not sure if using VPN (US based PIA) helped it go through or not although I don't see why it would. Roaming phones tunnel back through for a US IP anyway, so my iPhone shows up as an AT&T IP.

I guess it's a good idea to always have a dual platform setup