Bar capitol U with combining character display issue

In Keyman developer, when I test my desktop keyboard for southern madi, the bar U with combining characters (e.g acute or grave) does not display correctly. See screenshot below. It does display correctly for bar i, bar I and bar u. It also displays correctly in MS Word. Is this a bug or what?

I forgot to mention that I am running Keyman developer 16.0.138 on Windows 10.

I don’t know what font the test window uses, but that sounds like font behavior. You can right click in that test window to change to a font you would normally use.

@Kent_Schroeder If you want to send me your keyboard project, I can take a look. (I’m not sure if a .zip file makes it through our email system or not.)

I second Lorna’s suggestion. I think the default font in the preview box is Consolas (the Editor Character Font), which doesn’t do a great job with combining diacritics:
Click on Font… and select something like Charis SIL, and you should be happier:

Yes, it was a font problem. Thanks, Lorna, Jeff and Dave for your help. It is resolved.