Summary
Error
OBM 2018.05 is forwarding events to BSM 9.25. These events are received fine but the instructions tab is emptry - as it fails to retrieve the instructions.
OMW seems to manage forwarding events including instructions, but forwarding from OBM 2018.05 is not working.
Cause
When retrieving instructions from OMW/OML, their specific web service interface is used to get them.
OBM doesn’t have this interface (completely different WS technology) and BSM 9.2x didn’t have an interface at all.
So even if OBM would have one now (but there is still no public API for it) BSM wouldn’t know about it and still not able to use it.