Make sure buttons register clicks

[severin-lemaignan]

Reported by Charlotte:

The pause, play, skip buttons occasionally need to be pressed twice in
the app (not using the laptop keyboard). I assume that it's a similar issue
to the experiment running app... but it's definitely more annoying here!
And I think it can then lag quite a lot resulting in me being way out of
where I wanted to be (also 'cos sometimes you don't need to press the
button twice?)