This is a hail mary, but has anyone encountered this cart behaviour? I've been working on it with 2 different consultants AND NetSuite and we can't get to the bottom of it. Customer logs in to website. Adds Item 1 to cart. Then adds Item 2 to cart, and in doing so, Item 2 replaces Item 1. If they continue to item 3, that will replace Item 2. There is nothing in common with the customers it is happening to. I've checked logs, script executions, changed settings, signed in as the same customer and attempted to recreate. Nothing.

Try disabling any extensions you have deployed or try running the website from source and verify the default behavior there first.

Check if any client script is running on your webstore (without your being aware of that).

Yeah I've seen this in 2 different accounts, both had scriptable cart running which was adding/removing line items

@Bryce I totally missed these notifications. Did you do anything to resolve, other than turning off scriptable cart? Which would cause other issues for us since we have a script that determines tax on items in the cart.

Well it wasn't the actual scriptable cart that was the issue, more that our script was adding line items improperly

Got it. Thanks. I'm a new hire at this company and their set up is a nightmare. So many scripts and workflows on top of each other. They used NS professional services for the SC implementation last year and apparently they've had random issues ever since. And big surprise, support isn't much help.