Panasonic Toughpad FZ-G1 with EM7305 draining battery very quickly after GPS week rollover update

We are using FZ-G1 panasonic toughpad with windows 8.1 operating system and EM7305 modem. There is a user built windows service running on the toughpad, which was previously reading GPS data from NMEA COM Port without any issue. The problem occurred when we updated the device with GPS week rollover update to correct the date. After the update that windows service started consuming 50% CPU and another windows defender service Antimalware Service Executable started consuming 30% CPU. They are draining the battery very quickly. Before the update these services were only consuming 1 to 2 % CPU respectively. If i disable the NMEA COM port user built windows service comes down to 1% usage but Antimalware Service Executable still remains at 30% CPU usage. Is anyone else facing the same issue ?

The GPS Week Rollover update didn’t change anything else other than the GPS week. Not sure what GPS application were you using and if it uses Windows Location Sensor or NMEA message for location fix. From your description it looked like you are still able to get location fix while NMEA port is disabled. Maybe your original setting has NMEA disabled by default but it’s somehow re-enabled after applying the GPS
Week Rollover update?

Haven’t heard of anyone else with the same issue though.

Our application has been reading NMEA COM port directly in a timer after 5 second interval. If we only initialize the COM port and open it even without reading it in the timer it starts consuming CPU. Which only goes down when we close the port. Something has definitely changed as the same code was working for last 3 years.