I always updated thru PC & Garmin Express and always got data field and some parameters reset...
I can't believe this has happened yet again FFS!!! Just done the latest software update, and I've lost all my data screens again, PLUS they've 'improved' the method of setting the fields so that it's even more difficult to change them back.
It's my device Garmin, leave it alone! Definitely never ever buying one of these again.
I have the Edge 820 - with similar problems. Solved it by downgrading to a previous firmware, then on restart when the device automatically downloads the latest firmware hitting the X to refuse the upgrade. Now restarts ignore the new firmware and are fast - as is the whole device.
Not sure on how you'd do this for the Edge Explore - maybe its the same as the Edge 820... Anyway if you search for looigi's advice on this site for the Edge 820 you'll see detailed instructions. Previous firmware is available here: