I’ve got multiple sonoff zigbee temp sensors, all working well, except one I’ve put outside. Another one I’ve got inside is just 2m next to it, so don’t think it’s range. There are two zigbee plugs nearby to serve as ap.
It’s winter here in NZ so perhaps it’s too cold or humid? Or is it the double glazing / insolation?
Could be the battery? Try changing that and see how you get on.
Even new devices I’ve found can sometimes have poor batteries in them when they ship.
Thanks, will give it a try. Yes, I already had to replace one of the batteries after a month or so.