Hello,
i try to use my instinct with an Tempe Sensor, but the connection ist not reliable. There is no constant connection, even if the sensor is only inches away from the watch. Starting the temperature widget, everytime it shows Temp. Not Connected. Although the pairing takes a very long time so at the moment using the Tempe sensor with my instinct is useless.
I use a Tempe Sensor with an Garmin Etrex 30 too and there i have no such problems. There both always constant connected and pairing process is very fast compared to paring with my instinct (I know that the tempe sensor sends only data in intervals but with the instinct i have to wait minutes).
I think that the Implementationon is not as good as with other garmin Products. For me that is very sad because since the dropping of Ant+ support on Android 9+ Phones that was a reason to buy the instinct watch to monitor the temperature.
Maybe you could improve this with an software update.