Warning: Zigbee channel 20 utilization is 99.96%!

You can get budget and (openwrt) support but not with a broadcom soc like with your device!

Before buying router/wifi hardware one of the few (only?) things to do is to check if the device is supported - if not it is a NO BUY (for me).

Omitting openwrt on router/wifi decreases the possible lifetime of a device drastically in most cases.

And what happened in between?