Could not connect with specified SSH details

[ElucGeek]

I'm running the configurator in docker on my desktop ubuntu and try to connect to a VM on a NAS on the same local network. The VM get a dedicated IP address on the localnetwork.
With terminal I can SSH to the server but the configurator cannot and give this error:
fail: BTCPayServerDockerConfigurator.Controllers.ConfiguratorController[0] SSH This machine error Renci.SshNet.Common.SshConnectionException: An established connection was aborted by the server. at Renci.SshNet.Session.WaitOnHandle(WaitHandle waitHandle, TimeSpan timeout) at Renci.SshNet.Session.WaitOnHandle(WaitHandle waitHandle) at Renci.SshNet.Session.Connect() at Renci.SshNet.BaseClient.Connect() at BTCPayServerDockerConfigurator.Models.SSHClientExtensions.<>c__DisplayClass0_0.<ConnectAsync>b__0() in /src/BTCPayServerDockerConfigurator/Models/SSHClientExtensions.cs:line 28 --- End of stack trace from previous location where exception was thrown --- at BTCPayServerDockerConfigurator.Models.SSHClientExtensions.ConnectAsync(SSHSettings sshSettings, CancellationToken cancellationToken) in /src/BTCPayServerDockerConfigurator/Models/SSHClientExtensions.cs:line 44 at BTCPayServerDockerConfigurator.Controllers.ConfiguratorController.TestSSH(SSHSettings ssh) in /src/BTCPayServerDockerConfigurator/Controllers/ConfiguratorController.Deployment.cs:line 123
Any idea why the configurator get a connection aborted by server but not the terminal?