Full Sync Problems wih SAP

We have noticed that we have a problem with the synchronization with SAP.
Due to several errors, we took a closer look at the log and discovered the following message:

"Process task FullSync failed"

However, the job VI_SAP_SAPMandant_FullSync runs without problems.
In our productive environment we use IM version 6.1.3.

What else could we examine to further narrow the cause of the error?
Has anyone ever had a similar behavior and can help us?
What ensures that the FullSync stops without the job running on Frozen?
Many thanks for your help!

Kind regards