Thanks for the screenshot. Do you have the same issue with Firefox in Troubleshoot Mode? Are you running pro version of Windows? If so, you should have Windows Sandbox enabled for testing. https://www.howtogeek.com/399290/how-to-use-windows-10s-new-sandbox-to-safely-test-apps/

All sites work for me. see screenshot What security software are you running? You can also boot to safe mode with networking and test.

https://shop.sportsbasement.com https://us.muc-off.com/

worked Sunday doing nothing different.

taking https://byrna.com/ and changing to https://byrna.com/support gives an page on site, but clicking on say products gives blank page.

same for https://www.asp-usa.com/

I tried downloading the newest version yet again (now up to version 128.6). Not only do my windows not open, now none of my tabs work at all! I can't get into any of my bookmarks. I've tried everything. I am using an iMac running Monteray version 12.6.7.

Three months of bad tabs, and it has just gotten worse. I'm not a new user. I've used Firefox since version 3 or 4, so for many years now and on four or five different Macs over the years. But Firefox is now useless, so I will have to switch to Safari, which I have never liked. I am pissed!