I just got a chance to catch up on this thread and it sounds like people are having much more success with 18.21 which is great. I have received confirmation that the change in behavior between 17.X and 18.18 was due to a bug fix (yes, you read that right!) in the zigbee stack we use.
The good news is now that I know this I should be able to keep the Xiaomi sensors working when we do release the zigbee firmware in the future. Does anyone know if the sensors have been known to check in less frequently than once an hour? In my testing it always seems to be under an hour.
I received the Xiaomi gateway but haven’t set it up yet because all the permissions the app requests make me nervous. Have other people just bit the bullet and done it? I was thinking about setting up a spare phone with a new account.
I use https://www.silabs.com/products/development-tools/software/simplicity-studio and hardware from Silicon Labs but it’s a bit on the expensive side. This thread talks about some cheaper options that I haven’t tried personally.