Finally, AMD's motherboard partners have begun rolling out new BIOS updates to fix the widespread USB stability and connectivity issues. However, the current revisions are still in Beta form, with final firmware revisions due in April.
The firmware addresses widespread USB connectivity issues present on a number of Ryzen based systems equipped with Zen 2 or Zen 3 CPUs and 400- or 500-series motherboards. The problems center around random dropouts for USB-connected devices that impact several different types of devices, including unresponsive external capture devices, momentary keyboard connection drops, slow mouse responses, issues with VR headsets, external storage devices, and USB-connected CPU coolers.
The new BIOS patch appears to address the USB 2.0 controllers on 400- and 500-series motherboards. We still aren't sure if other USB devices, like USB 3.0 headers connected to the CPU directly or other USB 3.0/3.1 controllers, were affected. Also, there is no information yet on whether or not the fix has any impact on performance.
When checking to see if your motherboard has the new fix, your board maker should address the USB 2.0 fixes in the description of the latest BIOS on the board partners' web page. The fix's presence is harder to detect because AMD did not update the AGESA code with a new version — instead, this fix still runs on the latest ComboV2 126.96.36.199 AGESA code.
But be patient; most boards still do not have a new BIOS ready with the new AGESA code, with only a few 500-series boards (and no 400-series boards) having the update at this time. Presumably, it will be a few weeks before all mainstream 400- and 500-series motherboards receive the update.