Edge Explore not recording date/time in .fit files

[Pasley68]

My Edge Explore has stopped recording date and time in the .fit files recording rides. Fit files are not in plain text so I converted the last couple of rides to .gpx using RideWithGPS, GPS Visualizer, and GPSBabel - and the same in each case:- no date or time.

Speed, distance, and time of day still get displayed OK while riding. Just no date or time in the recorded .fit file.

I have had this unit for 3 years and reliably recorded nearly 500 rides.

I tried a factory reset to no avail, and made sure I had the latest software.

Has anyone had this problem and if so how did you fix it?

[Pasley68]

Update,
It appears that mounting another device that uses WiFi (and maybe Bluetooth) on the handlebar next to the Garmin interferes with the GPS signal (or reception of the GPS signal. In this case I was using a small action camera next to the Garmin. Despite having WiFi switched off on both devices there was interference. Take the camera away and Garmin OK; put it back and immediate interference.
Cheers
Adrian