Saw this thread pop up and thought I’d add the recommendation of the Nyce motion/temp/humidity sensors, the ceiling mount type, which have been rock solid, although they don’t seem to be available any longer.
But, I believe the 3rd generation Iris sensors are the same as the Nyce sensors, although physically different and use CR123a instead of the AAA batteries.
There’s a thread on them here:
https://community.smartthings.com/t/iris-sensor-motion-temp-humidity-13-tx-ebay/198149?u=blkwll