I didn’t remember V9 having the ability to add your own UD fields. I thought that was introduced in E10. I also don’t have a V9 to run to check.
Are you sure it was extended UD Table Maintenance, not Extended Properties? When you added the UD field, did it force the _c at the end of the field name?
Something else to check, I seem to remember that V9 had two “admin” type programs. There was the Epicor Administration Console that you did the screen shots for. I believe there was also another admin program, don’t recall what the exact name, but I believe if you go to your Windows Start menu, it might have been under the Progress menu group. I believe Vantage 9 still ran with a Progress engine even if you were using SQL - it wasn’t until 10 that they removed Progress and sped things up quite a bit.
Did the _UD and the dbo view get made on the sql server? In the current process stop starting IIS would reread the schema. Maybe there was something like that also on the progress version.