Hi Rod,
In the past when I have had this issue, I used Malwarebytes to get rid of these issues. Sometimes, it took running in safe mode with networking or without, to do it, but it worked.
There are other programs out there and you should use what you're comfy with. Malwarebytes is just my own choice here.
This is another good reason I have more than one browser installed. If one gets unusable, I have others to fall back on to try and repair the issues.