This is on XU4 v6.22. I suspect nothing to do with DietPi or Jackett, probably a Mono problem or incompatiblity. Only clue is this log entry:
18:03:13.0719 Error Jackett.Common.IndexerException: Exception (acgrip): Authentication failed because the remote party has closed the transport stream. —> System.Net.Http.HttpRequestException: An error occurred while sending the request —> System.Net.WebException: Error: SecureChannelFailure (Authentication failed because the remote party has closed the transport stream.) —> System.IO.IOException: Authentication failed because the remote party has closed the transport stream.
at Mono.Net.Security.MobileAuthenticatedStream.ProcessHandshake (Mono.Net.Security.AsyncOperationStatus status, System.Boolean renegotiate) [0x0008e] in :0
at (wrapper remoting-invoke-with-check) Mono.Net.Security.MobileAuthenticatedStream.ProcessHandshake(Mono.Net.Security.AsyncOperationStatus,bool)…
…and it goes on like this.
Before this I had uninstalled and reinstalled several times with same result.
John