Rectify Platform Scheduling calendar Error

I am in need of assistance to fix an issue on my platform. The problem occurs when trying to reschedule a class with a particular tutor - it just doesn't show any response. The issue is not specific to a certain device, it happens on both desktop and mobile. Sadly, there is no error message to indicate what could be wrong. Potential freelancers would need to have a proficient understanding of troubleshooting platform bugs and ideally have experience in dealing with scheduling systems. As this issue affects the usability of the platform, demonstrating skills in user testing would be ideal.