I had it happen with the R&D starting charger,
when I loaded r&D it charged the tech,
then went and did a couple of the combat testings noticed low charge,
went back to start to get charge,
did not charge (and also the charge level on the batteries of the charger was low),
added geo wireless chargers to the charger,
started to transfer from the NEW wireless chargers only.
hope this long description helps