I had about 90 minutes of no data (I was so sleepy, not sure if there was ??? but I don’t recall seeing that). I eventually woke up enough to tap on the xmitter repeatedly. Within about 5 minutes I got readings and continued uninterrupted for the next 6 hours til I changed out the sensor (didn’t fully trust it at this point).
Tech support had a hard time giving me the root cause since I couldn’t even tell them if there were ??? when it happened.
My question to them was could tapping improve the connection from xmitter to sensor and they said no. they thought the cause could be either “out of range” or sensor got moved a tiny bit from a bad spot (muscle, scar tissue) to a good spot but it had been working fine for 7+days.