You would correct this one page of Sku Grid items at a time, using multi item actions. So I'd recommend following along with this video (but where it references Amazon, just assume Walmart) https://www.youtube.com/watch?v=Zyc-P1ZC4Z0
- In short, you'd set your grid to view 1000 items per page.
- Then select Walmart from the 2nd filter on the page so that it only displays items where Walmart is the supplier
- Then use Multi Item Actions to Select All Items on a Page.
- Then Multi Item Actions --> Update Store Options
- Select Walmart
- Choose Walmart Only
- And Update the Items
- Repeat steps 3-7 for each page of 1000 Walmart items if you have that many.
- Then you can do a Recheck ASAP https://www.youtube.com/watch?v=IdG9JArejE0 on all items under batch options and then force reprice all items in your account using batch options --> force all items to reprice https://www.youtube.com/watch?v=1zK5V3D_XGg.