Product Size Resetting Between Product Page and Checkout

Technical Q&A

Topic summary

Issue: Product variant size intermittently resets to “Small” between product page and checkout. Customers select larger sizes (e.g., 2XL), but paid orders record “Small,” leading to fulfillment errors and complaints.

Scope and impact: Happens sporadically; most orders are correct, but enough failures occur that the store owner now emails all customers who ordered “Small” to confirm. Damages customer experience and adds manual work.

Reproduction and testing: Store owner cannot reproduce the bug in test orders. An external tester also confirmed normal behavior and shared a screenshot. The problem appears only for some live customer orders.

Patterns observed: The incorrect size always defaults to “Small.” Initially suspected to be triggered by changing color after selecting size, but cases occur even on products without color options.

Status and ownership: Root cause unknown (unclear if Shopify platform, theme, or other). No fix implemented. Discussion remains open with no confirmed resolution or workaround beyond manual order checks.

Attachments: A screenshot was shared to show successful testing, but it is not central to diagnosing the issue.

Summarized with AI on February 14. AI used: gpt-5.
1

Hi there…

I have been suffering through a recurring issue with product sizes being reset between someone placing an item in their cart and checking out. What I mean by this is that a customer is selecting a size 2xl (for example) but when the order is subsequently paid for it is listing an order for a size Small (always a small). If the customer notices and sends a ‘can you change the size’ request then all is good, unfortunately not everyone (in fact I would say probably a majority) either don’t read or don’t bother opening their order confirmation e-mails resulting in annoyed customers demanding to know why they have received a small when they ordered a different size.

This is happening fairly frequently, enough that I have started sending out e-mails to anyone who orders a small to double check that is in fact what they wanted, which is far from ideal and doesn’t give a very professional impression.

Anyone else had a similar experience they managed to fix? I don’t know if it is a Shopify problem, or a theme problem or what. I’ve tried placing test orders myself but have been completely unable to replicate the issue no matter what I try.

Very puzzled and frustrated.

2

Hi @Hellwood_Outfit ,

I tested and it works fine.

Screenshot.png
Screenshot.png1240×267 49.6 KB

did you solve it?

1 Like
3

Sadly not.

All works fine when I test it out and 90% of the time works fine for everyone else but I still keep getting the odd order that does it. I did think it might be because customers were picking their size and then switching the colour of the t-shirt, but it has happened on orders that don’t have a choice of colour option.

Thanks a lot for having a look for me though. Much appreciated.

1 Like