The MSKU is not the SKU - Cannot locate the Merchant SKU to correct this

So I am at a loss for this one. Our Inventory Ledger report has the MSKU line which should be the SKU, given that these are FBA items. However, one item on our report is giving me a string of numbers and I don't know where it has gotten this from. It is giving accounting a headache when balancing inventory since it does not correlate to anything product related.

I went through our flat file data and history and I have no idea why this is propagating on the report. Our SKUs are words that correlate to the item on our manufacturing order sheet. Everything I have read tells me that the SKU and MSKU are the same. Clearly they are not since we do not use numbers for a SKU.

Does anyone know how to correct MSKU data and where this is located?