Why do transactions fail? Help for an old guy

Oops! An invalid Txn hash has been entered. Undefined

What does this mean on Etherscan? Does it mean that gas prices jumped while I was trying to execute a transaction? Trying to stake ETH with Lido through a connected Ledger to MetaMask. Will I lose my full transaction and all my ETH or just the gas? Do I have to leave my Ledger connected to approve the transaction when gas fees lower or can I just connect it later and approve the transaction? Any help is appreciated