I had the same problem on 21 January 2019 I receive a replacement for my Ledger Nano S due the firmware upgrade, ...
Do You mind explaining "replacement due firmware upgrade"?
Because the old hardware version of Nano S should be replace in order to upgrade the firmware
Um that has not been my experience. Mine is an original Nano S still working just fine. All firmware upgrades have been done through the ledger app and only through the official app.
I think you found your issue.