When people choose other revisions in the revision slider, parts of the page, but not all is reloaded. Gadgets listening only to a page reload, but not to the diff changing do not work anymore after the change.
Add an info to https://www.mediawiki.org/wiki/Extension:RevisionSlider to let people know they should really make use of the wikipage.diff hook and not just listen to full page reloads, in order for their gadgets to work well with the revision slider.
The revision slider is a feature that adds a visualization of all revisions to the compare screen. Revisions are represented as bars on a line and can be selected using two pointers. The revision slider was originally prototyped by the WMF Community Tech team and then handed over to the WMDE TCB team, as it is also a solution to fulfill a wish of the German Community Wishlist: https://de.wikipedia.org/wiki/Wikipedia:Umfragen/Technische_W%C3%BCnsche_2015/Artikel#Anzeige_aller_Bearbeitungskommentare_im_Diff