Selecting slides in Lightable: Windows 10

I must be doing something wrong in Lighttable; I am unable to select a slide and use the criteria for that slide and apply it to others. Slide will simply not ‘select’. I’m using V.3.4.1.1 and I’m using Windows 10 Pro on a Dell laptop.

I also seem to have an issue with the software scaling to my screen but that is another story.