Home Assistant OS very unstable

Good to see it looks like you sorted it out.
About the USB3. Good that you use an extension cable, I’d strongly advice everyone to do so for the Conbee or any other Zigbee dongle when you use USB3. Creating some distance from the USB3 interference will make the Zigbee signal more reliable and enables you to easily pick a good spot for the antenna as a bonus.

Also see this post: