Not an answer to your question, but definitely worth trying if you haven’t done this already. I did it to and I never have issues with Zigbee, to be honest.
A little help to optimize your zigbee network.
To start with, Zigbee in homey is on channel 11, WiFi’s three non-overlapping channels (1, 6, and 11) use the exact same frequencies as ZigBee channels 11-22.
Other hubs, like tradfri and hue, can also ‘live’ in other channels. Try to set them.all to 11, and make sure you sort out the best wifi channel to use.
This means that you need to optimize your wifi / zigbee network. This could solve Wifi dropouts, and zigbee not working correct. This will…