First and foremost, read through this thread. From your description it doesn’t sound like the common issue seen here since the light is still working, but you’d have a better idea if this may be it or not. The switch connects to the hub via zwave, but it uses RF to communicate from the switch to the canopy module.
My hunch here is that you may have accidentally enabled local protection on the fan button. You can check this by going into zwave-js, find the node for your lzw36, go under configuration and look for [70-112-0-31] Local Protection. It should say None.
As a last resort, I’d do a full reset on the switch itself instead of an exclude.
EDIT: I guess I should have kept reading! LOL Still read through that thread. I had this issue almost daily until I changed my WiFi channels and Zigbee network channel. Now I only run into it about once a month and it only lasts a few seconds.