I have a forerunner 945 and use it as hr wrist to broadcast to my edge 540. it worked well before firmware 21.17. After update to 21.17/21.18, it can't connect to the edge 540 anymore. But it works well with my edge 1000.
interestingly, when i turn off my cell phone's BT, it could be connected again. There must be some kind of interfere of BLE signal. Hopefully it could be solved soon. 