[theevilsharpie]

Ryzen desktop CPUs support ECC as long as the motherboard supports it.

What it doesn't support is registered (including load-reduced) DIMMs, which is the most commonly available type of server memory. Unbuffered ECC DIMMs only.

[hypothesis]

Unless you get yourself a “desktop” Ryzen that is just a rebranded APU with graphics parts shutoff, e.g Ryzen 5500.

Admittedly, AMD does list ECC as unsupported on that one, but most motherboard vendors will only warn you about APUs not supporting ECC RAM.