I too am facing this issue, I'm on Mac. I have been using EA 5.03 (don't even dare to update to 5.08 or upper) on a Mac, after upgrading my Mac to High Sierra, I am facing product list not in alphabectical order and other modules are also facing the same.
I thought the newer version of EA might solve my problem and almost wanted to purchase the upgrade, I downloaded the trial version and tested on Mac OSX Mojave, to my horror it is even worse. If I go to "Account Payable" module, linking the Purchase Order did not even filter the list to the specific supplier list, I will show all other suppliers, making everything in a big mess.
Every Software update / upgrade should be an improvement, but it seems that NCH is making every update of their software become worse.
If NCH is listening and reading, if your customer is complaining, they still want to stay on with your software and wants you to improve. If they are not interested at all, they would just leave you alone to mess up everything and move on to other alternative software.