OnBeforeInsert of ItemLedgerEntry weird behaviour

I've made a method that I call inside the OnBeforeInsert of the Item Ledger Entry table.

This method checks the Iventory of the associated Entry to a given date, and doesn't allow the entry to be created if its gonna make the inventory negative (I know this functionality already exists, I'm just doing an extension where I need to replicate it to work with any given date).

I filter the Item Ledger Entries for that item and date limit, and then sum up all the "Remaining Quanity"s.

For testing purposes I created a brand new item, and through the Item Journal I gave it 10 units with the positive adjustment.

Now imagine after posting that, I try to post a Negative adjustement of 6. The "Remaining Quantity" of that previous Positive Adjm. Item Ledger Entry will be equal to 4 (instead of 10).

It seems like the the Neg Adj is balancing the previous positive even tho this whole calculation is called inside the OnBeforeInsert of the ILE table.

Any ideas on how to solve this?

I'm gratefull for any help given.