CJ44 Exceeding budget unexpectedly

Hello
I wonder if anyone can help?
I have my overhead keys set up correctly and now have no exempt cost elements from AVAC
In the configuration for transaction types for AVAC control, I have transaction type 05 as a warning (3) at 100%
However, I just tested this and ran an overhead posting in CJ44 for an actual posting near the available budget, and expected that when I ran CJ44 that I would indeed get a warning that I was exceeding the budget.
I received no message and the overhead posting of 15% from the WBS was posted, exceeding the budget.

Does anyone know why this may be the case? I thought transaction type 05 was controlling documents and that these would be included in the overhead run???
Many thanks in advance
Mark