Monero

Hi, I've just paid for Mullvad VPN (personally recommend) with XMR. That looked like this:

1. I copied the address (one time subaddress) and the amount, checked if everything matched (and it did) and pressed send.
2. On my Ledger I checked the fee, accepted, checked the amount, accepted, checked the address... REJECTED, because the address was different.
3. Repeated the step above probably 2 times, installed ClaimAV and started full scan of my machine for malware.
4. Because the Monero Wallet GUI was freshly installed from official Arch Linux repo and it showed the right address I decided to still accept the transaction. Worst case I lose 10 €.
5. While the transaction was pending I tried to prove payment using LocalMonero's block explorer and I got an error. So I basically got hacked and lost 10 € ...
6. Checked Mullvad VPN app and... it was paid???

Can someone explain me what just happened? My ledger showed a different address than what I copied, but the transaction still went to the right person. I started using Ledger only a month ago and I haven't been paying with it much. If this is all good and right, how can I tell if I'm being scammed on my Ledger?