I just developed this same problem! I do a lot of streaming and am very well-protected with UBlock Origin, Bitdefender Anti-Tracker and the free version of Avast. In the last few months, many sites throw the URL Scam (well Avast throws the messages that it has blocked the Scam). What is blocked is constantly different and sometimes I can't even get into a site because the URL itself is a "Scam" or a socket is a "Scam."
I upgraded to Avast Premium for the free two-month trial which just ended. It made no difference in re to this issue. I am getting down. I feel like my computer is infected. I saw that a Coupon extension was running, it must have downloaded with another program. turning it off and deleting it did not make any changes to the scam messages. I started snipping the messages and saving them but it became ridiculous. There are so many! Maybe the streaming sites I visit are infected with an adware virus.
When the issue first started, it was only on one particular site that also incorporated discus for comments. I received a lot of Discus scam messages and then Discus disappeared from the pages that have comments. I see no comments now, and I have to say, it is refreshing not to see all the inane negative political remarks when the site has nothing to do with politics. Ya know the drill!
I don't know what else to say. The bell on the Avast warning messages is so loud, I jump out of my seat sometimes. Now sites that I have been going to for 5 years throw messages. What's going on! I, of course, followed the advice above - no change, alas.
Thank you!