Are you still running macOS 10.14 Mojave on any of your Macs? If you are you may be one of the people that is having problems with the recent Mojave Security Update and the update to Safari 14. Because of these issues, Apple has just released Mojave Supplemental Update 10.14.6 which is confirmed to fix these issues. You can download it in Software Update on your Mac. This article explains some Mojave issues that are fixed.