This sounds like a darktable installation or database problem rather than normal editing behavior. One community reply noted that some basic modules/history items were missing (such as color profile/orientation entries), which suggests the setup was not behaving normally. Another reply also pointed out that the button used in the video was for creating a style from the history stack, not compressing it; that error appears if darktable thinks the image is unchanged. In the reported case, deleting the darktable databases and reinstalling/updating to the latest version fixed the issue. So the most likely cause is a corrupted or broken darktable database/configuration, possibly combined with confusion over the history-stack controls. Back up anything important first, then try resetting/removing darktable’s database/config files and updating or reinstalling darktable.