Hi,
Can you please let us know if the same posting rule is used for IHC and non IHC posting?
From the screenshot it looks as if the posting rule requires posting in subledger.
How have you set up this subledger posting in the EBS config.
What I would advise you is the following:
Use 2 different posting rules for posting IHC and non IHC related postings
you can use payment notes to identify the document to be cleared in the subledger.