I have them connected to home assistant via SmartThings, they both keep becoming unavailable. I’ve been pinging both devices for 24 hours and they don’t actually go offline.
2.4ghz and 5ghz are separate, the router is about 2 meters away, the home assistant connection is wired and stable, the only thing I can put it down to is the API not unless anyone has anything else to suggest.
It’s only been a few hours but there have been no unavailable events with LocalThings where as SmartThings has had 2, which isn’t as bad as it has been
Since the network connection and ping tests show both appliances are completely stable on your separate 2.4GHz band and close router, it definitely points toward either cloud API rate limiting, OAuth token refresh dropouts, or SmartThings integration polling issues rather than local Wi-Fi drops. Have you checked the Home Assistant core logs around the exact times they flip to “unavailable” to see if SmartThings is throwing API timeout or rate-limit errors?
I have the same issue in HA, constant drops, i noticed because power sensor is no longer updating. In smartthings power is also not working unless I open the energy section in the app and rhen HA updates the sensor. Does your energy reporting in smartthings work?