Hi pdkm2000, It ''may be'' a GPU related issue. This is from [https://www.pcworld.com/article/3214635/ryzen-threadripper-review-we-test-amds-monster-cpu.html PCWorld]: "Threadripper’s crazy core count has another unintended consequence: AMD says some older games crashed in its tests. This isn’t a problem with Threadripper, AMD notes, but the games themselves, because they just can’t handle the number of CPU cores. To address this problem, Game Mode essentially tells Windows to recognize only 8 of the 16 CPUs in the system. An updated Ryzen Master Utility lets you switch between Game Mode when it’s needed for older games, and Creator Mode when you want all of your CPU cores and more memory bandwidth." Check with [https://support.mozilla.org/en-US/kb/performance-settings?as=u&utm_source=inproduct Firefox's performance settings] for some ideas in Firefox.

You might also be interested in this: [https://www.ghacks.net/2019/05/20/firefox-webrender-rollout-begins-with-the-release-of-firefox-67/ Firefox WebRender]