It happened during my 20-mile ride today after I made a brief stop. The device was never turned off during the brief stop. I only realized what was happening about 2 miles later when I noticed the power data was stuck at 50W and there was no change in my HR. A hard power off and on reset it and it then recognized all the paired devices. During the "freeze", it was still collecting GPS and temperature data. Only data from external devices connected via ANT+ and BLE were not collected.