Couple questions: what happens when you try a record where that field has a value? Also, what type of GDB is the data stored in? If in an enterprise gdb, does you user have read permissions to the domain?
Just to verify: In your table of contents, right click on the feature class and select Design; choose Domains and that will show you all the domains the the gdb. Click on fields and that will expose what Domain is assigned to what field in that feature class.
That should just about do it....