https://wccftech.com/amd-opens-ryzen-5000-desktop-cpu-support-on-x370-b350-a320-am4-motherboards/

More than a year after their launch, AMD has finally opened up Ryzen 5000 Desktop CPU support on their first-gen AM4 300-series platform.

It was a long battle between AMD and its board partners on whether they should or shouldn't enable support for Ryzen 5000 Desktop CPUs on first-gen platforms. Due to heated backlash, consumers did bring Ryzen 5000 CPU support on the 400-series platforms but the 300-series motherboards were never officially supported.