It looks like some global CSS may interfere with the Scheduler CSS styles. You can try to disable the global styles temporarily to see if it is the case.
Also, it looks like you are using an old version of DayPilot (pre-7.9) that uses <table> for the row header. Since version 7.9, the Scheduler uses absolutely-positioned divs which are less sensitive to global CSS.
Let me know if it didn't help.