Problems with intensity minutes?

I was using my FR935 yesterday while my F5plus was charging.  I was wearing the watch while doing an indoor training ride and my FR935 did not record any intensity minutes.  I reset the device to factory defaults yesterday afternoon and tried it in parallel with my F5+.  In order to isolate the situation I turned off the BT link on both watches.  The F5plus was able to pickup the HR and added to the intensity minutes, but my FR935 did not.

Has anyone else had problems with their FR935 detecting and recording intensity minutes lately? I am on FW 19.10 with BLE/ANT/SNS version 6.90.