Could you please provide the code you used? If you try the same in one of our examples, do you see the same result?
just open this one as an option https://bryntum.com/examples/scheduler-pro/constraints/
There is a global variable schedulerPro which you can use in console for testing. It also possible to edit code at runtime in code editor (see </> button on toolbar) if you want apply your preset too.
I used your config file and the scheduler-pro in our example demo and worked with no issues, but in your code, you have several listeners that I had to remove because there they are not in the configuration (assuming that they are in the component code)
Could you please share a sample project with all your configuration and component (you can add it to one of your demos), then zip it and share it here?? With all the info that you shared so far, it's not related to your configuration, maybe something in one of the timeaxis event listeners handlers, but need the full project code to confirm that to you.