I ran into this same mess during a bathroom reno last year. It gets confusing fast if you have different people adding stuff simultaneously. Are you guys trying to use a single login across multiple devices or are you on separate accounts? One thing that helped me was disabling the 1-click buy thing so we didnt accidentally order before the cart synced. There's a neat extension called Cart To Link that basically turns your cart into a link.

To add to the point above: the struggle is real with Amazon Business. Quick question though - are you guys sharing one Prime login or are you on totally separate accounts? It makes a huge difference for how the cart treats the inventory. In my experience doing this for three house flips, the native Amazon setup is basically useless for real-time stuff. A few cheap or free ways Ive handled this over the years:

• Use the Share-A-Cart extension. Its free and you just text a code to the other person when the cart is ready.
• Check out Multi-User Cart for Chrome. It actually syncs the session so you both see the same thing live.
• Honestly, just turn off 1-Click ordering. Someone always accidentally buys the wrong sink at 2 AM without checking the cart first. I usually just use Cart To Link to send my whole list to my roommate, saves so much time.

Honestly, Ive been really satisfied using specialized browser extensions for this. I tried a couple that work way better than the default Amazon lists for session sync...

• Share-A-Cart: Works well because you can send the entire cart via a unique ID. Very happy with the reliability.
• CartShare: No complaints, it handles live updates smoothly. Both make remodeling way easier tho. Just let me know if you need help setting them up!