VPN or Proxy Service Error Message - Unable to watch Amazon Prime Video

I’ve never had a problem accessing Amazon Prime Video más de T-Mobile Home Internet plan with the 5G Gateway N1.

A month ago I started having intermittently getting this message:
Your device is connected to the Internet using a VPN or proxy service. Please disable it and try again. For more help, go to amazon.com/pv-vpn.

I would clear my browser cache and restart it, problem solved, sometimes I needed to reboot my computer but nothing more. I have never had a problem with Netflix, Apple+, Disney, or Hulu only Amazon and as of this evening nothing I try fixes it except switching to my backup network provider.

Any idea why only Amazon blocks my access by mistakenly thinking I am using a VPN or proxy service?