I started having a problem with my 735xt where I would log an activity on the device, it was there on the watch history, then as soon as I connected the USB cable it would clear the fit files from the activities folder and not upload them, basically losing the activity or activities.
After resetting the watch and reinstalling garmin express, this did not solve the problem.
Turning off garmin express and trying to look for the files via mass storage also does not seem to work.
I tried garmin support who said they had not come across the issue before and have now replaced the watch.
New watch has been fine for 2 weeks, now doing the same thing.
I have tried tried connecting the device to 2 different PC's and changing the anti virus software but no difference.
It is as if the windows filing system is removing the files before they get uploaded, very weird and not normal windows behaviour, and needless to say does not happen with any other usb mass storage device.
Anyone else having this problem? and has anyone got a solution?