Why does Bluetooth no longer detect devices?

[AC Question]

Since the latest update I had been having trouble with my HRM dropping out during my workout. I would have to turn Bluetooth off, then on again and it would sometimes come back. Now the phone doesn't even recognize the HRM through Bluetooth. I cleared the cache and no change... won't recognize the device. I am using a Polar Heart Rate Monitor with the Polar Beat app... have been for years. Needless to say this little "hiccup" is quite a pain. Also, messenger force closes every time I try to open it. And several other apps are screwy. How could an update this buggy even be released?

 

[B. Diddy]

Welcome to Android Central! Which phone? I'd suggest a cache partition wipe, but need to know the phone model first.