After updating my HTC One M9 to Android 6 I am no longer able to turn on the Bluetooth radio. I have navigated to the Bluetooth On/Off settings but the the toggle button only turns gray for about 10 seconds and then returns to the off position. It was working properly before the upgrade.
I also tried to run the Wahoo Bluetooth utility. When started it indicates that it needs to turn on Bluetooth, when I accept the dialog, it shows "Bluetooth Permission Request/ Turning Bluetooth on..." and then it hangs there.