Matlab GUI runs extremely slowly

Hi. I've written a Matlab GUI, which was working really well before but has started to run extremely slowly. I've made changes to the gui by adding functions etc, but haven't changed the gui layout itself, and I can't think of any reason it should run slowly. Even just moving the cursor across the window is making the mac wheel of death come up. Pressing a button on the gui is a trial of patience. I've updated to Matlab 2018 but it hasn't helped. In fact it probably made it worse.

I've removed any window motion, window button, window scrolling callbacks. I've turned datacursormode off. I've turned the helper rendering off. I can't think of what else to do, but it's really making the gui unusable. I've written gui's before and never had this problem.

Any ideas?! Perhaps I should provide more info but I'm not entirely sure what would be useful. The gui has a few buttons, drop down lists and a figure window. When the user selects a drop down list, and then hits the run button, previously loaded data is processed in some way and the results shown on the axes.

Any help would be much appreciated,

Katie

[Catherine Davey]

I should also mention that I've run the profiler, but it seems to report the results without including the wait time for the mac colour wheel. For example, I might sit there for 10-15 seconds waiting to be able to press a button, and when I run the profiler it says that the operation took 0.7 seconds. That's probably significant but I'm not sure how?!