I often fail to spot collapsed blocks because the visual signposting of collapsed blocks is rather subtle. You have a slight halo around the bullet point, as below.
Is there way to make these more salient? I am thinking of two possibilities, firstly to make the halo brighter / a different colour, and secondly, to add some bread crumbs (preferably brightly coloured) at the end of the collapsed block.
Could this be done by CSS? I can’t seem to find any themes which provide better signposting for collapsed blocks, so I suspect not.