Certain variants not showing up in Product > Inventory?

[bvstudios]

Hi, I have a Product with 5 variants and 2 of the 5 variants are not showing up in our inventory list. Any idea why that is happening? The variants and quantities show up just fine on the Product page but not the Inventory list. 

Thanks

[Bob_]

We use the Inventory reports to check stock levels against our warehouse system reports and have noticed this month that stock from July gets disappearing from the reports and the Inventory page. Changing the quantity to 0 saving then setting back to the quantity we have and saving again seems to fix it.