Scheduled refresh fails

Hi,

i have a report that is failing on scheduled refresh. Manually refreshing works.

The Error:

xxxx Report has failed to refresh.
Failure details: The last refresh attempt failed because of an internal service error. This is usually a transient issue. If you try again later and still see this message, contact support.

Received error payload from gateway service with ID 3027064: A non-serializable exception was encountered.;A non-serializable exception was encountered Error resolving type specified in JSON 'Microsoft.PowerBI.DataMovement.Pipeline.InternalContracts.Communication.NextResultRequest, Microsoft.PowerBI.DataMovement.Pipeline.InternalContracts'. Path '$type', line 1, position 159. Could not find type 'Microsoft.PowerBI.DataMovement.Pipeline.InternalContracts.Communication.NextResultRequest' in assembly 'Microsoft.PowerBI.DataMovement.Pipeline.InternalContracts, Version=3000.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.. The exception was raised by the IDataReader interface. Please review the error message and provider documentation for further information and corrective action

Setup is using On Prem Datagateway in a Cluster (2Gateways), the Dataset is connecting to a SQL Server with SSO Authentication. 
It was working until the kerberos auth failed after November Updates, the Auth was fixed with installing kb5008601 on all DCs. Manual Refresh Works again since then, but scheduled refresh never picked up again. Disableing and later Enableing it didnt change something. 

Anybody knows where to look, the error message does not give me any idea.

Thanks