Starting anew with more information and refinement of my issue. Today I started to get Malewarebyte website blocked pop-ups. Started when I tried to access www.att.com from my Opera browser. The listed threat domain was netcheckcdn.xyz. This has happened on Vivaldi browser now and at least one other website that I entered (can't remember what one). Multiple times on my desktop and when I tried www.att.com access on my laptop I received the same blocked website pop-up from Malewarebytes.
I have been able to get to www.att.com, so that website has not been blocked.
I have now run a Farbar scan and can attach it's scan files. Any assistance would be appreciated to help resolve this as it is of concern for me that this has started. I will also attach the most recent Malewarebytes Threat scan file ( it found no threats) and the website blocked log.