Like I said, Firefox takes 6 seconds to open at startup. After that, it blinks with delays while in a tab of any kind. I've been an adamant Firefox user and proponent for years, but after spending hours upon hours trying to determine and fix the problem with absolutely no success, I've given up and have moved to Chrome. I'm further discouraged with the only way to report a solid problem is to open a topic for "discussion". I am a seasoned technical computer and system engineer with mores years experience in IT than most people's age reading this. This is not a discussion, it is a report of a failure in Firefox. For those that are about to write and ask if I restarted it in safe mode, ran the troubleshooter, uninstalled it and reinstalled it, started it with a new profile, removed any extensions installed, removed themes, add ons and any other possibly interfering software, restarted my PC (Windows 11), removed cache/cookies/ and whatever, checked internals, checked hardware, checked the OS, check for corrupt or incomplete Visual C++ software or install, checked for malware, disabled virus software, checked for conflicts with your Internet security software, the answer is yes.... many times over.