N/search : Filter expecting numeric value was removed, as non-numeric value 'Wa' was provided.

Hi all, so I'm using an N/search script to find records with matching serial numbers. However, the filter is being removed because apparently the value of the serial number needs to be a number and not text which seems.. really dumb. Unfortunately it seems the filter I was using of inventorydetail.inventorynumber is for the id of the serial number on the list of serial numbers, and not the number itself. So I'm trying to get to inventorydetail.inventorynumber.inventorynumber but those are not valid joins.

Does anyone know how I can achieve this? I've attached my script for reference and pictures of the logs. For the script I'm focused just on the search aspect of it, trying to go through the serial numbers on the item receipt I'm saving and use those to search for matching sales orders.