I have an 81 transmitter and am able to restart sensors following the procedures outlined in this video. Please note that I have a Tandem pump so I have included it in the instructions.
Stop Sensor on Phone. Stop sensor on Tandem pump. If sensor session has already ended, that is OK.
Using a guitar pick (I wasn’t successful using a Contour test strip because it kept bending), slide from the fat end of the transmitter until you hear the sensor clip unlatching and lift up the transmitter. Do on both sides.
Wait 30 minutes with the transmitter out of the sensor.
On phone, provide the code (take photo) and then Start Sensor.
Don’t start on pump. It will catch up and join the session.