FWIW, I haven’t ever seen that occur on this site. I use Firefox on Windows 10 computers, without any ad blocker installed. I do have Firefox set to ask permission before allowing Adobe Flash to run on any site (which I generally do not grant, as allowing it to run often results in obnoxious talking ads and/or slow performance), although I don’t know if that has any relevance to this issue.
Regards,
-- Al
Regards,
-- Al