F1 web servers blocking (ISP) Quantum Fiber (US) IP addresses?

This morning I discovered I could not log in to the member portals on F1TV or access any member content on the F1 websites via App or direct website using my home internet provided by Quantum Fiber in the US. Through troubleshooting with the F1TV support chat, and providing them my IP they suggested my ISP may have 'ad blockers' active.

I checked my connection through a mobile ISP (AT&T data - using mobile phone as a wi-fi hotspot) and all F1 Services worked.

After clearing cache on all my devices, trying different web browsers not fixing the issue while using my home internet - I proceeded to verify no ad blockers or security features were installed on my router (Asus) or fiber modem (provided by ISP).

I also then spent 40mins with my ISP's tech support and they couldn't identify the issue.
I then decided to use a VPN server in my same city to see if that changed anything, and everything worked.

Therefore I can only conclude that F1 is blocking a legitimate USA based ISP for some reason, and I either have to change ISP's or continue to use VPN's to get my subscription services to work!

I haven't had this issue prior to now, and have been able to watch all the races and other shows this season.

Now F1TV support is offline, and it's BOT only. Guess I'll try to engage with them another time.