My first guess would be someone edited the entry transaction and validated it, or edited the screen directly and validated it. I suppose someone could have modified the OSOH window  and done a global validation, or someone could have done a dictionary validation on everything or just the OSOH object or an action code that included that entry transaction.

For the entry transaction, it's Setup > Sales > Entry Transactions > Orders. You can select the transaction in question and see when it was last modified via Utilities > Properties.

For the screen, the order lines are going to be of the SOH4 type. Development > Script Dictionary > Screens. Filter the Abbreviation column to SOH4, and one of those should include your entry transaction code. You can look to see when those were last modified as well.

I'm not familiar with those EDI fields, so I'm not sure if you can hide them on the entry transaction setup. If so you could do that and save+validate. If not, you should be able to change them on the specific screen (although the change will get reset if your entry transaction is validated again). Find the fields and either change the Input to 'Hidden' or the method to 'Form' (not 'Form and Table'), so they show in the popup window but not the grid.

Hope this helps.

Thank you! This helped me narrow down who made the change to the system.