Change in the document type is making the change for "Unknown" document type

We created a document type – Sample File in DEV environment. We checked in the database in the table - [WM10].[dbo].[BizDocTypeDef] and we found that we have a different primary key (TypeID). But, whenever we are making any change in Sample File, the change is getting reflected for the Unknown document type which has different TypeID. Similary, when we are trying to find out the document type using the webMethods service –, we are getting the details for the “Unknown” document type, be it type name which is “Sample File” or type id which is derived from the database.

This issue gets resolved when we start the Integration Server. But after some time, the issue again comes up front.

Sample File has attributes - sender and receiver which are not mandatory.

Sounds like a run time bug, since it’s fixed when IS restarted.
I’d suggest that you open a ticket with SAG, see if a patch available.