I logged in to have a look and it seems odd but the IA adjustments don't seem to have impacted their qty on hands or their GL. I can see that there is a detail transaction for about -1,400 items but their on hand quantity seems to have stayed stable and I can't see where there was a GL entry made to support the adjustment.
The only thing that looks odd (so far) is the detail transaction report showing the qty adjustment but that does not for some reason seem to have impacted qty on hand. We also ran stock status and valuation and both those don't seem to have been impacted by the pre-migration utility which kicked out an IA adjustment.
Seems weird.