Hello
Thanks for developing LimeSurvey.
I have an instance with version 3.15.5+181115 in https://surveys.debian.net and we're using it for a survey about the future Debian release artwork.
The survey consists in one question type Ranking, the options are shown as HTML images (loaded from the original places where the artwork is stored, wiki.debian.org).
The default theme for the question was resulting in a suboptimal layout, so we chose the advanced_ranking theme for this question. This makes the available options appear in a group and at the bottom the other group for the chosen ranking, instead of in two columns (left and right). Then, the help tip becomes confusing, because it reads:
"Double-click or drag-and-drop items in the left list to move them to the right - your highest ranking item should be on the top right, moving through to your lowest ranking item."
but our participants don't see "a right column", they move their chosen options to the bottom, and those are ordered left-to-right.
After receiving several reports about the issue, we have hidden the tip, and added "You can use double-click and drag-and-drop to select/move items." to the question text.

My suggestion is that the help tip does not assume a particular spatial layout (I suppose (but didn't test) that even with the default theme, in small screens as the mobile ones, the page will show groups up-down instead of columns left-right). "You can use double-click and drag-and-drop to select/move items." would be my proposed text but I realise it's not very explicative either...