Make sure a specific Variant is enabled on your eBay channel dashboard in Shoppingfeed to be sent to eBay.
Note: You must turn on the parent product for any of its variations to be listed.
Check-out your Manage Colors & Sizes tab to make sure the parent-child relationship was setup properly.
For us to send variation drop-downs on eBay properly, you must determine a correct association for each unknown field found in your Source Feed:
Is it a variation? If yes, is it a COLOR (aka variation attribute 1) or a SIZE (aka variation attribute 2)?
If not, then map it with NOT A VARIATION, for example, {Title} field. Typically is not a variation.
Feel free to access your Settings tab to make sure the default mapping was not changed.
It is typically pre-installed by the system for every eBay user.
Note: If you have any products that use two drop-down options (Such as Pillows who use Size AND Pattern), please make sure to assign one attribute as a color and the other attribute as a size (ie. assign Size as Size and Pattern as Color) This will help Shoppingfeed understand any products that use 2 variation attributes (drop down options) on the store-front and be able to replicate that in the outgoing Datafeed to the marketplace/channel.
If all the above requirements were met, feel free to initiate a manual eBay channel update by hitting the Update button on the channel dashboard and then review your listings on eBay again in 30 minutes.