The address was 3KoLhz2bEkmsoSWHAfV3Xi6X239NKhXiHk. However, when they checked the xpub - they were unable to find that address....
On my Ledger - I used the 'sign message' function to check all the addresses used for BTC segwit and the 3KoLhz address is indeed listed.
The xpub was ...