Core issue: Cart quantities intermittently duplicate (1 item becomes 2). Removing the “extra” unit can cascade, removing or adding quantities on other line items.
Original context: Store using the Broadcast theme (bridetribes.com.au). Merchant receives ~5 customer emails per week reporting cart malfunctions; issue is not consistently reproducible.
Diagnostics so far: One tester could not reproduce on the cart page. Another suggested potential JavaScript errors with an AJAX cart (cart updated via JavaScript without page reload) and asked for specifics on what “upsets the cart.” Merchant clarified the removal action affects other items in the cart.
Additional reports: Similar, intermittent behavior on multiple themes—Prestige (paid), Dawn 2.4.0 (free), and Turbo 9.0—suggesting it may not be theme-specific. One user noted “Buy It Now” cleared the cart after adding items.
Reproducibility: Merchants often cannot replicate; customers sometimes notice only post‑purchase.
Status: No confirmed cause or fix shared. Open questions remain around specific JS/AJAX errors, conditions triggering duplication, and the “Buy It Now” interaction.
I can see how this might happen if there’s some JavaScript errors in the theme with AJAX carts. We can cover that shortly but what has me interested is this comment you made:
“When a customer tries to remove the extra item, it upsets the whole cart”
What does “upset” mean in this case? Something breaks? What do you see? Any context here may give some clues.