The sender was having some troubles to withdraw using the base58 format, which starts with a 8. So I used this website thinking the worst that could happen is me having to manually sweep the address with the private key
And I gave him the correspondent "standard XMR" address shown on line 15, which starts with a 4.
Transaction has plenty of confirmations and was not automatically detected by the wallet. So I'm trying to import in Monero Gui a private key using as the address the "standard XMR" public address, and using the private spend and view key from the wallet itself (note, it's a different address starting with 4 than the main account shows). It doesn't work, it just errors out and doesn't let me proceed.
Was the coins lost for good?
I think I need a way to calculate to hash the private spend and view key from the subadress itself, like it's very crudely explained here
After that it should just be a matter of importing in the wallet, if anyone has any have idea how to do that please share...