Yep. I run Firefox. Maybe it was a Firefox update that caused the popups.
Firefox has a pop-up blocker in its add-ons.
Click the orange box in the upper left corner, and then click add-ons. There are many of them, but I have six or seven.
They’re easy to initiate and easy to customize. Pop-up blocker is one of my favorites. It tells you when it prevented a pop-up, and it gives you the option of exempting sites that use pop-ups for other than ads.