Ok. File Explorer might not have the correct columns, but it should show width and height of your jxl if you right click the file, go to Properties, then Details. Then you'll be able to see what the Windows shell knows about your file - any file. DOpus can't see anything it can't see unless it has a plugin for it to override Windows shell.
I'd recommend you install Mojo-Chan's excellent JPEG-xl plugin though as plugins are always better than relying on what Windows sends you.
Try the right click for AIFF as well. I didn't have any, so I downloaded this one. It shows me channels, bit depth, bit rate, and audio sample rate. Duration also, but it's under Length.
No worries, on DOpus 13 you can manually add Windows shell File Display Columns. Go to DOpus preferences -> Shell Properties and find Length. Check it on. Make a Length column instead of Duration. You should now see it.
Blame Windows (Windows Media Player) for this one.
Metadata names not matching is a common issue. But you can use this method to add anything else Explorer can find to DOpus.