Why is the wrong product variant being added to my cart?

Topic summary

Issue: Selecting a specific product variant (e.g., Blue/M) added the default first variant to cart on a Shopify store (binzzy.com, Shrine theme). The user has limited coding experience and sought urgent help.

Check: Another participant tested the site and saw the correct variant being added, asking if the problem was product-specific.

Root cause: The store owner identified a conflict with the Shopify app UpCart. UpCart’s form was overriding the site’s add-to-cart form, leading to the wrong variant being added.

Fix/Outcome: Disabling the UpCart app resolved the issue. The cart now adds the selected variant correctly.

Next steps/Status: The user requested Shopify to contact the UpCart team about a compatibility issue (at least with the Shrine theme). No confirmation of an app or theme-side fix yet. Discussion effectively resolved for the original poster via the workaround (disable UpCart), with open questions about an official fix from UpCart or Shopify.

Summarized with AI on January 13. AI used: gpt-5.

when I select a certain variant (Blue / M, for example) it just adds the default first variant instead of the variant i’ve chosen. i’ve tried looking online for a solution but it looks like its possibly a line of code? i have no experience with coding although i have added some custom css scripts to my store before using chatgpt. i need this fixed asap so could someone please help me???

binzzy.com is my site if anyone can help me find the code/reason that is causing this

binzzy.com is my site if anyone can help me find the code/reason that is causing this

Hi Josh, I checked your website and it seems that it work right, the correct variant is added, are you facing the problem with a certain product?

hello, thanks for the quick response, i ended up figuring it out

the problem was with a shopify app (upcart)

basically their form overrided my websites form which was causing the problem so i just disabled the app

if anyone from shopify could get in contact with the upcart app and let them know this is an issue (for shrine theme at least) that would be great

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