Shopify Search & Discovery Showing Source Variant Options (NOT Complimentary Variant Options)

[PILLOWPIA]

Hi, I am trying to display an automatic discount using Search & Discovery. When someone buys a pillow cover, I would like to promote buying the pillow insert at 30% off. I've set up a Source Product and the corresponding Complimentary Product. And I've enabled quick add. 

When I click quick add, it opens the Complementary Product pricing but the Source Product variant options. Am I setting this up incorrectly?

Ideally I would like to add both to cart in one click. I have tried bundle apps but they conflict with our other discounts and I don't love how the backend works (setting up draft orders, etc.). Any feedback/other ideas would be helpful.

Here is the popup showing the wrong (source product) variant options (ignore the actual options, I am trying to do away with the cover only, with insert options), they should read 12x20, 20x20 etc. see 2nd screenshot:these are the actual product options when I go to the product page:

Thanks in advance!