Forgot to report this earlier: Copying from the editor puts something like
Version:0.9 StartHTML:0000000177 EndHTML:0000000746 StartFragment:0000000213 EndFragment:0000000710 SourceURL:http://127.0.0.1:65532/_anki/legacyPageData?id=1741757776368
in the clipboard.
If you have more than 2 learning steps, the middle steps now repeat the current step, instead of being the average of the previous and current step.
It should probably be mentioned that this is about the Hard button.