See my comments in this thread – https://moosh.im/f/topic/android-ble-connection-problems/

I need to find my other Android tablet and check it to determined what Bluetooth version it is. I also need to check the Mooshimeter Bluetooth version as well.

I am starting to suspect that part of the problem is that the Mooshimeter is Bluetooth 4.0 or Low Energy Bluetooth. I recently purchased a Ion Bluetooth Speaker for my son and tried to test it out one of my Android devices that is not Bluetooth 4.0 Low Energy and it was interesting that my Android could not see the Ion speaker at all. While the Bluetooth Spec clearly shows that Bluetooth 4.0 should be backwards compatible with earlier versions of Bluetooth. I think there are non compliant Bluetooth 4.0 devices and/or devices that have firmware bugs in them.

I would try to reset the Mooshimeter, put it in shipping mode, then wake it up from shipping mode and try to reconnect.

I found that if the meter was in Logging mode, I would also sometimes have more problems connecting via Bluetooth, not sure why, but seems the Mooshimeter may have been wrapped up Logging too much if I had a fast polling speed.