I wrote about that 1099 issue somewhere on this forum because it took me a bit to figure it out as well. I’ll have to go find that post in Jan. LOL
ETA - Here it is…
https://test.sellersasksellers.com/t/payoneer-1099k-walmart/3189/5?u=asv_vites
Can somebody tell me how delete all my items from Walmart in bulk?
Right now I can only retire them 25 at a time?! 
Not sure. How many you got on there? You’re leaving the marketplace?
about 4000.
No I uploaded a file thinking it would match to an existing UPC and put me on the correct listings.
However the catalog is a mess.
Some items got matched to single packs, others to (pack of 2) (Pack of 4) 8, 24…whatever.
So bulk uploading is not going to help. So I figured I delete them all & start fresh.
But the back end is SOOOOO SLOOOOOOOOOOOW. I’m dying.
Yea, it sucks. It took me literally 3 months to get 4 items listed correctly so I wish you luck.
There isn’t a lot out there in terms of support, tips / tricks either.
Delete is not really availabe.
Walmart also throttles your ability to edit to about 10 an hour.
So if you’re frustrated…that’s part of the reason.
I’ve heard that the delete button magically appears and then disappears. Like they’re trying to do it and then nope.
So zeroing out inventory is a way to quickly make them disappear and then retire.
Build a spreadsheet to set the inventory to zero quickly