Hey there! When visitors go to my store on mobile and select the non-primary variant and click "add to cart," it's adding the primary variant to cart.
A workaround is to click the dropdown, select the second variant, TAP THE SCREEN ELSEWHERE, then tap add to cart. Most people aren't recognizing to tap the screen elsewhere to "set" their selection. They just tap the variants, tap the one they want, and tap "add to cart." I've not seen this issue previously so I don't' know if it's new or just unreported. This isn't an issue on desktop. How do I fix this?