We need more information

What wallet are you using?
Have you tried with Chrome extension and with ledger live? Electrum is a good option too.

Did you bought ledger nano from the original retailer?

Was it legacy or segwit? Are you using he right derivation path?

It may be a problem related to derivation path.

Did anything unusual happened when you generated this address? Did you get this address when signing a message with ledger of did you click receive?

Few days ago a ledger user had the same problem because he used an address that appeared when he signed a message. It was like the 150th of that path. He found it using iancoleman.io/bip39 tool