There is an issue with Full Screen mode and e.g. Apple Dictionary.
When used Command-Ctrl-D in normal window, works fine (shows definition of the “focused” word);
but when used the same in the Full Screen mode, this shortcut (or result) doesn’t work.
The same is true for other useful options, like Sorter Notes. I can’t make notes in the Sorter when reading something in the Full Screen mode. When invoked, the Full Screen mode is going back to normal window. Fixing this would be very helpful.