My lightning adapter is in good condition and is working with an iPhone X on iOS 13 with the same HDMI cables.
However, on my iPad Pro 10.5 with iPadOS 13 beta 3 screen mirroring or video playback isn't working.
Has anyone else experienced this?
Lightning Digital AV Adapter Not Working on 10.5 inch iPad Pro
It seems like on beta 3 (public beta 2) on iPad Pro 10.5", no lightning accessories work at all (USB camera adaptor, etc). I haven't tried lightning headphones yet but that would be a good test.