Problem adjusting sliders on Lightroom Android on Chromebook

Using Lightroom Android on Asus C302 Flip Chromebook.  I have a subscription and all of my photos and albums sync fine - no issues.  The most annoying issue, however, (besides not being able to save/open adj brush presets, common to LRCC) is that I cannot move adjustment sliders on edit with the mouse.  At least not easily.  

I assumed that I could left-click and drag the center ball on say Exposure or Clarity and drag the setting to the left or right.  Not so much.  I tried double-clicking on the text to enter directly.  No good.  The only way I can move an edit slider is to single click on the slider line to the left or right of the 'ball'.  This moves the slider glacially in the desired direction.  If I become impatient (I do) and click too fast, the app reads it as a double click and resets the setting to the center.

Does anyone else have this problem?  Am I missing an obvious setting?  I have searched for a keyboard shortcut that might let me move the slider, but have come up empty.  Is there a set of keystroke combinations that move the sliders? Needless to say, I try to do all my editing on my Windows desktop (where things work), but I occasionally find myself on the Chromebook.