Cannot select characters (Steam)

qandols

In at least Under the Sea node I cannot click the right arrow to select my 1 and 2 star characters. The screen just sort of bounces back and jitters. And suddenly it works again. Weird. And now it struck again. In every node in Simulator. You just cannot press the right arrow to flip through your roster.
Update: It lasts a minute or so and then it works again. Go figure...