Hello,
from posted information, you have the symptom from the SAP note:
1128989 - "command timeout exceeded" with DBMRFC session mode
- Check on the workaround in this note.
- I recommend on workaround, as you will run the liveCache/client on appl. server upgrade as one of the steps from upgrade SCM system & the issue should be resolved.
Best regards, Natalia Khlopina