Cannot remove watchtower client node

Support and Troubleshooting
1

Hi all,

I have one watchtower client node (tower) configured which is no longer existing. And one tower which is working.

With advanced settings in Lightning Node, there is a trashbin icon that I assume is for removing a tower. However clicking that icon, nothing happens.

Using lncli I can see both towers are configured:

umbrel@umbrel:~$ sudo docker exec lightning_lnd_1 lncli wtclient towers
{
    "towers":  [
        {
            "pubkey":  "020redacted",
            "addresses":  [
                "s5mredacted.onion:9911"
            ],
            "active_session_candidate":  false,
            "num_sessions":  0,
            "sessions":  [],
            "session_info":  [
                {
                    "active_session_candidate":  false,
                    "num_sessions":  0,
                    "sessions":  [],
                    "policy_type":  "LEGACY"
                },
                {
                    "active_session_candidate":  false,
                    "num_sessions":  0,
                    "sessions":  [],
                    "policy_type":  "ANCHOR"
                },
                {
                    "active_session_candidate":  false,
                    "num_sessions":  0,
                    "sessions":  [],
                    "policy_type":  "TAPROOT"
                }
            ]
        },
        {
            "pubkey":  "037redacted",
            "addresses":  [
                "k3alilredacted.onion:9911"
            ],
            "active_session_candidate":  true,
            "num_sessions":  1,
            "sessions":  [],
            "session_info":  [
                {
                    "active_session_candidate":  true,
                    "num_sessions":  1,
                    "sessions":  [],
                    "policy_type":  "LEGACY"
                },
                {
                    "active_session_candidate":  true,
                    "num_sessions":  26,
                    "sessions":  [],
                    "policy_type":  "ANCHOR"
                },
                {
                    "active_session_candidate":  true,
                    "num_sessions":  1,
                    "sessions":  [],
                    "policy_type":  "TAPROOT"
                }
            ]
        }
    ]
}

I managed to deactivate the tower “020…”, however I cannot remove it:

umbrel@umbrel:~$ sudo docker exec lightning_lnd_1 lncli wtclient remove 020redacted
{}

All I get is these curly brackets as an answer. And if I list the towers, it is still there.
Any ideas how to get rid of it?
I tried also to remove it with the onion address appended, then I get:

[lncli] rpc error: code = Unknown desc = cannot remove last tower address