There are times when users edit transaction records and the fields are rapidly flickering making it impossible to edit them. The field switches from Memo to PO # without any user action. Fields and Save button become unresponsive. This behavior is reproducible when using Google Chrome and Mozilla Firefox. It is also possible that this is caused by enabling the Multiple Shipping Routes feature without setting up the prerequisites.
Before reporting this to NetSuite Support, try these steps first:
1. Navigate to Setup > Company > Enable Features > Transactions > Shipping & Receiving > unmark Multiple Shipping Routes box > click Save
2. Navigate to Setup > Accounting > Setup Tasks > Shipping > mark Charge for Shipping box > click Save
3. Navigate to Setup > Accounting > Taxes > Set Up Taxes > mark the Per-Line Taxes on Transactions and set the Default Tax Code to Non-Taxable > click Save
4. Navigate to Setup > Company > Enable Features > Transactions > Shipping & Receiving > mark Multiple Shipping Routes box > click Save
You may visit the SuiteAnswers article 9291 Multiple Shipping Routes for your reference.