You already are confusing two things. the computer aka Windows crashing or Pro Tools crashing. Which is it? and because you are not clear here who knows what answers from folks will be about? And what exact crashes are you getting? what Windows bluescreen or AAE or ASSERT error or what *exactly* happens?
You should pick Mac or Windows based on the environment you are most comfortable working in. Both can be stable if you set them up correctly and troubleshoot them well when they have problems. And Mac are typically more work to keep up to date with and more hassles due to macOS changes and processor hardware changes, so if you are having troubles managing a Windows setup I would NOT switch to Mac expecting it to be easier for you to manage.
Standard troubleshooting instructions is under "help us help you" up top on each DUC web page. Start there, post a SiSoft Sandra report as expected, is the system *fully* optimized? Describe exactly what is happening and what troubleshooting you have tried.
Have you tried to get help here or from Avid support before? From a very quick look the only post from you that seems relevant is stuff hanging (not crashing?) with a white screen? Like this thread
https://duc.avid.com/showthread.php?t=415405. And there I can see what looks like you might be misunderstanding how to troubleshoot for plugin related issues (you need to move the .aaxplugin files out of the plugin folder, just not using a plugin in a session does not mean much, installed plugins can still cause grief and do so frequently, and no mention of trashing prefs, or testing from a new admin user account, so who knows if you did those or not but some glaring obvious basic things at least not being discussed). And a 64 core Threadripper likely places you outside of the standard usage/coverage so maybe you might expect to turn up some problems, but hopefully they only happen under extreme load/thread count. But I'd focus on working through standard troubleshooting there. As much as I love AMD EPYC and Threadripper platforms that's a pretty extreme environment for Pro Tools, I wonder if it's worth the hit in clock rate and thermal throttling etc. vs. more modest core counts. What are you doing with all that? Running huge composition/VI sessions? Are you making use of freeze/commit to tame some CPU load?And you should double check that the DIMMs in that build are on the VQL, I think they are and any difference is just retail packaging/naming, but check... end-user memory tests very often do not find problems and do not mean the memory is known good. At 256GB with Threadripper I'd have gone ECC with memory,... that's a nice cosmic ray detector you have there. I'm curious how you have you handled the "rotated" Threadripper chip and what heatsink/fan/case you used for cooling. Are you monitoring CPU core and DRAM temps? (I'm a fan, pun intended, of the Lenovo P620 in large part because they have very nice packaging and Threadripper and DRAM cooling, even with a power supply that could do with more grunt, not for Pro Tools use for me though).
If you have other past thread that better covers your problem(s) then can you link to it here.