I have an Edge 820, with all Garmin sensors, HR, cadence and speed. I have no other electronics on the bike. The speed sensor continued to lose connection, and re connect 12 times on a 30 minute indoor training ride on Zwift. I just installed a replacement Garmin speed sensor and I have the exact same problem. The HR and cadence sensors seem to keep connected just fine, it's just this durn speed sensor that keeps losing connection. I've just read some of these other comments about the connection working better when the sensor is installed on the front wheel, but on the trainer, that is not a good solution. I've had this same trainer and bike set up for the past two years without an issue, it's just lately the speed sensor has been an issue. Yes, I have changed batteries several times without much luck. Do I have two bad sensors? What is the operating range of the speed sensor? Can things like the rider or water bottles "block" the signal getting to the head unit?