No clue whether or not this is a bug. But Listary 6 doesn’t highlight files or folders. I vividly remember Listary 5 had that as one of its highlights.
It does work in Explorer, but I don’t use this archaic piece of software. I use Directory Opus. Most of Listary 6 works within Opus. But the highlighting does not. And it is a important feature. Could you please integrate this back?