I had something similar happen. I picked up some adware while switching over antivirus programs. My Chrome browser was infected even though I was using Firefox when I would see the ads. I had to uninstall Chrome, run Malewarebytes Adwcleaner, check for clean scan, then re-install Chrome, recheck for clean scan. Without uninstalling Chrome, the adware hid in there somehow and would reappear even after Adwcleaner tried to delete it.
Only Adwcleaner found the culprit. The regular Malewarebytes and Avast scans came up clean. I don't think using a pop-up blocker it the long term fix for this kind of issue because you probably want to get rid of the adware off your PC, not just not see the pop-ups.