4.12 Custom UProperty Category makes property invisible on AnimNodes?

I recently switched from 4.11 to 4.12. I have several custom AnimNodes that I am using. These nodes have many properties which I am used to setting in the Details Tab in my blueprints. With the switch, however, these properties don’t appear. I get an empty details tab except for the “Node” under the Settings Category. After some investigation/experimentation, I found I could get my properties to show up if I used a ‘standard’ property (like Settings, Link, etc), but any custom text string Category makes the UProperty vanish.

This wasn’t an issue before this version. Is this a new restriction, or is it a bug? Or is there something new we need to do to Categories to get them to work? Any help would be appreciated.