I flashed the latest bios on it yesterday. I think it's the ram the steel series from patriot I've read a lot of people having bother with it. I've got a Ryzen 5800X3D I've just bought I'm going to see if it works with that. But I'm sure I had this 5600X working with team group ddr4 3600mhz in an MSI x570 build last year.might be the ram only has xmp profiles on it...amd can run xmp profiles so not an issue..is the bios up to date on the aourus elite mobo..might be why you struggle running 3600hz speed...my am4 with a 5800x runs 3600 no problem...
a bit like when am5 came out, runningat 6000 speed was problematic...3 yrs later and 6000 now the standard you buy and some boards can run at 8200 speed, and b650 boards can run them too with bios updates wich patch the memory controller software