That sucks, I was considering a Threadripper or even Ryzen 9 for a secondary PC, but seems like an Intel chip might be a better option.There have been plenty issues with ryzen 5/7/9 and b450 boards. Usually mobo related. Bios not up to spec etc.
I personally had 2 different 450 boards and a list long of issues. Sold the boards and dropped a X570 in and am a happy camper.