Scenario
There are instances that on Website, duplicate Shipping Items are seen on the Checkout while on the NetSuite UI, no identical Shipping Items found.
Solution
The main cause of the problem on the Website is similar values for the field Display Name/Code. While on NetSuite UI, Ship Name is used instead. In order to fix the problem, follow the instruction below:
1. Navigate to Lists > Accounting > Shipping Items
2. Click Edit for any duplicate Shipping Item
3. Copy the value for Ship Name
4. Paste the value to Display Name/Code