Showed my IT guy my cell popups, his thoughts follow:
He said it’s coming from the site, malicious code likely through a valid or bogus site ad. This code is written to target mobile phones/devices.
One way to verify is go into ‘desktop mode’ from your phone, the site should work fine. Many phones do that by clicking the three vertical dots at top right and selecting to view in desktop mode.
If it pops up on your phone, close your browser using phone controls not screen controls presented. It’s important to avoid clicking links, including links triggered by clicking a bogus ‘X’ presented on screen for close out.
Often new advertisers come to sites to place malicious code, but it can also come through valid ads, unknown to that company.
He thinks it needs to be stopped at the forum site level. If not already resolved it may take someone like him to do a quick forensics/repair (just like us changing
oil. ☺).
Fwiw…Best of luck. Brent