The Onceit Marketplace has very specific attribute requirements. Much development has been put in place to fit in with the Onceit Attribute rules. Consider this FAQ when troubleshooting attribute data for Onceit.
In most cases, the products won't list because the attribute data is not correct or not in the feed.
Scenario 1
https://support.omnivore.com.au/a/tickets/90729
Using some examples - simple wholesale with a Scent Variant.
https://ebaylink.omnivore.com.au/product/view?sku=1593113149491&retailerCode=simply-wholesale-2
After the recent development that Werner did 10/22.
Home» Home Decor» Candles & Diffusers
Accepted onceit attributes we pull in.
(1) black-raspberry
(2) black-raspberry-vanilla
(3) champagne-rose
(4) lime-coconut
(5) pine
(6) sandalwood
(7) scented-assorted
(8) sweet-pea-jasmine
(9) unscented
(10) vanilla
(11) vanilla-caramel
Outcome / Fix: because their scents were not close to the onceit scents we suggested asking if Onceit would add the simply-wholesale scent range into the onceit database.
If the scents were more of a match, using this method below would have worked.
Scenario 2
Same ticket as above.
Also simple wholesale with a bed size variant
https://ebaylink.omnivore.com.au/product/view?retailerCode=simply-wholesale-2&sku=10973936717
Home» Bedding» Sheets
The product variant had Size Queen or King and Onceit needed an attribute value for Size. You could only select one attribute at the product level, eg Single, Queen, King etc. Because none were relevant, and because we needed an attribute for each variant, in this case Queen and King, Werner did some coding to add the attribute to the variant, but you cannot see this on the product page, nor in the attribute mapping screens. You will only see it in the View Omnivore Data.
Other Relevant Reading.
https://support.omnivore.com.au/onceit-categories-not-supporting-variations-omnivore