Problems pairing two sensors of the same type

[PeterGamma]

Again a repeat, but necessary for clarification. A training tracker cannnot pair two sensors of the same type. I had the problem with two Polar OH1 sensors and two Polar H7 sensors. With Garmin watches for instance it is no problem to use sensors of the same type. I could solve the problem of using two Polar OH1 sensors, one recording sensor data, the other charging, by pairing one over BLE and the second one over ANT+. I had to remove the previous paring, reboot the smartphone and pair to the second Polar OH1 to solve the problem.