if scrollbars are set to "when scrolling", they fade out and don't come back in Creator's editor

1) go to System Preferences, General and change Show scroll bars to When scrolling
2) start creator, open a large enough file that you will need to scroll
3) scroll it. The scrollbar fades out afterwards.
4) now you can still scroll with mouse wheel or a gesture but the scrollbar never fades back in again
5) go back to preferences and change to Always
6) in Creator you will see a grey rectangle where the scrollbar should be, but still no scrollbar
7) close and restart creator and repeat the test. You will always have scrollbars now.
8) the setting "Automatically based on input device" results in no scrollbar, not even the first time, if I have a trackpad connected and the mouse disconnected. Should't it still show them during the scrolling, just for feedback?