If you see this warning, it means the wallet application you are using does not use the correct derivation path linked to the coin application you opened. Please verify that the derivation path is correct before you sign such a transaction.
Since Bitcoin app version 1.4.6 a vulnerability was fixed for all Bitcoin derivative apps. This version should not introduce any visible changes for Ledger Live users.
A new message The derivation path is unusual is shown when exporting public keys for a Bitcoin derivative that does not respect the coin type of the application. Likewise, a new message The sign path is unusual. Reject if you're not sure is shown when signing a transaction.
However, users of third-party wallets (Electrum, Magnum Wallet, etc.) might also see this warning message even if the public key or signature request comes from a legitimate wallet. This is due to the fact that these wallets use an incorrect derivation path, which can also be valid for Bitcoin. Unfortunately, there is no way for the app on your Ledger device to tell whether this path is legitimate. We encourage developers to derive and sign on the correct derivation path.