Your ledger might have disconnected.
Run the following tezos-client command to see connected ledgers.
tezos-client list connected ledgers
It should output something like the following when connected:
## Ledger `adjective0-animal0-adjective1-animal1`
Found a Tezos Baking 2.2.5 (git-description: "") application running on
Ledger Nano S at [0004:0002:00].
To use keys at BIP32 path m/44'/1729'/0'/0' (default Tezos key path), use one
of:
tezos-client import secret key ledger "ledger://adjective0-animal0-adjective1-animal1/bip25519/0h/0h"
tezos-client import secret key ledger "ledger://adjective0-animal0-adjective1-animal1/ed25519/0h/0h"
tezos-client import secret key ledger "ledger://adjective0-animal0-adjective1-animal1/secp256k1/0h/0h"
tezos-client import secret key ledger "ledger://adjective0-animal0-adjective1-animal1/P-256/0h/0h"