When entering Wolfgang's gym after going up a mighty stage (Wimpy to normal or normal to mighty) a visual glitch where a circle is placed in the corner of the bar on the gym appears. Bar as in the bar that appears when doing the timer challenge on the gym. It is visually the same as the circle that normally appears. So there are two of the circles on the bar when there should be one.
In addition to this at times when I correctly time pressing the button when the circle is in the middle of the bar the game would count it as a fail and Wolfgang would fall over. I have tried and tested it multiple times, it is not caused by pressing the button too fast in-between from each other or that it is pressed at the wrong time. This issue is a common occurrence as well.
note: The gym uses two boss statues.