I'm a little confused... you state:
It's possible that you accidentally loaded up the "legacy" Bitcoin wallet in the "Ledger Wallet Bitcoin" Chrome App and copy/pasted a "1" address from there... OR you loaded up the Bitcoin Cash wallet instead of the the Bitcoin wallet, and you got a "1" address (as BCH has no SegWit support).
The address I sent to starts with 1.
Where exactly did you get the "1" address from that you sent Bitcoins to if you have "always used SegWit"? It's possible that you accidentally loaded up the "legacy" Bitcoin wallet in the "Ledger Wallet Bitcoin" Chrome App and copy/pasted a "1" address from there... OR you loaded up the Bitcoin Cash wallet instead of the the Bitcoin wallet, and you got a "1" address (as BCH has no SegWit support).