Hello. Recently I found one strange thing that I faced for the first time.
I made two selectors, one for branch and one for UOM. Below is code for them

As you can see they have a selectors tag. One Acumatica default and one is made by myself.

During the test I have found one problem. I had this error

After some time of investigation I found one small problem in ASPX
ASPX created by customization project by adding grid:

And problem was with one control that Customization Project haven’t create by adding field

And after that everything works fine. But I have a similar one screen that have also a selector for Country DAC field with selector

And there is code ASPX code from this screen

But in this case the selector works fine. So it might be a bug but I suggest to check what customization project created if you have problem with fields but in code they looks good