I had setup Pi-hole and it was blocking something like 66% of my internet traffic which amounted to ads and spyware.

A couple of days later, it just mysteriously stopped working and I couldn't for the life of me figure out why. My theory is that AT&T detected my blocking and blocked my internet as a result. Is that too much of a tin foil hat theory? How can I know for sure?

I don't know too much about computer networking, only the basics.