I'm assuming your server and client are on Windows? What version of Windows is your client on? Does the problem go away if you try it 64 bit FileMaker Pro? And while I can feel the frustration, I would probably solve such a situation with a popover and virtual list. I think you are right in expecting it to work like it did in 12, but if it doesn't, about all you can do is submit a bug request and try to solve it in a different way. Does this work on some computer and not other ones or does it not work on any of them for you? If so, if you can describe the difference in the computers. Or can you create a sample file with just this layout and table/fields (no data) and duplicate the behavior and upload it here for us to try? If we can't figure it out here in the discussions, you might want to look for a FileMaker developer in your area to help out. FileMaker Consultants, Data Consultants, Database Consultants
Thank you for taking a look at my post.
I have stripped the file down removing all links and relationships with only 12 records. Even using the file as a stand-alone the list will work typing in value 2 on version 12 and not with 14 (32or64) regardless of which computer which is consistent accross systems.