I do remember having some issues with the bios resetting when I had upgraded my pc to this mb+3700x. But I haven’t had those issues since. I think upgrading to the f4 bios at the time fixed the resetting but I’m not sure on that. The bios boot times are quite long. For me it takes about 23s to get to grub. (Same time with fastboot enabled)
As for memory im running a corsair vengance 2x16 kit at 3000mhz (CMU32GX4M2A2666C16) without issues.