I am using an umbrel, and I have not been able to create a transaction that will include that UTXO. I have tried with LND itself, Thunderhub, Ride The Lightning, LNDg, but It seems it is not possible. I made the mistake to close a channel adding very little fee, so I am trying to increase its priority by spending the unconfirmed UTXO with a high fee. With Electrum I can easily do this, but seems that with LND it is not possible.