Move sliders by touch (Html viewer)

The transparancy sliders next to layers or folders and the basemap slider cannot be moved by touch in the tablet version (or desktop version). 

The only way to move those sliders is by pressing another part of the slider (do the slider moves to that point), but you cannot press and move it as you do on a smartphone or with the mouse on desktop. 

We use a Panasonic Toughbook with Windows as a tablet device with touch. 

Is there a way to get this working or will this be fixed?