Just made upgrade of system with lxqt as desktop.
Seems works OK except tray - when hovering over icons (e.g. battery status, nm-applet, ...) panel hides like if I move cursor up. No caption is displayed.
When I'm quick enough, I'm able to make right button click to get context menu of tray icon before tray hide.
I have hiding panel set in settings since first install.
I believe this happens due to a particular bug fix , and in part due to the 'tray' plug-in being "deprecated".
Please try and see if your applications works with 'statusnotifier' instead (a lot of GTK+-2 applications will not).
A hacky workaround (that I use myself) is to revert said fix, but I'm not comfortable including it in the official ebuild.
See also: https://github.com/lxqt/lxqt/issues/1812