Hello Dennis,
you could debug in oder to know what is the reason for offline approval not processed.
Put a break-point in PROCESS_DECISION method from /SAPSRM/CL_OFFLINEAPP_INBOUND class.
See KBA 1667378 - Inbound Offline approval does not process documents
As you are in EhP2, check also OSS note 1754379 - Offline Approval Inbound processing fails
If you use synchronous validation, you do not need to put a break-point: set field DEBUG_ON from BBPD_IMD_DEBUG table. An infinite loop will be triggered in IF_INBOUND_EXIT_BCS~PROCESS_INBOUND method (/SAPSRM/CL_OFFLINEAPP_INBOUND class).
Regards.
Laurent.