I have 5, 6 year old passports in service now...I had one fail due to me leaving the usb cable plugged into it while carrying it around in a backpack to work and the connector failed.
Eventually got it to work by direct wiring it.
The remaining passports just sit on a rack humming along...
I am aware of the temperature of these drives when working hard and will slow down the data or just pause for a couple hours to allow them to cool.
They can get so hot, it is uncomfortable to hold them...
Maybe that is your issue.