Greetins @turansaim
There can be many reason behind this. You will have to check the basics first. Please make sure that you are using the latest version of the product. If you are using the tutor pro then that has to be the latest version too. IF everything is okay then you have to check for plugin conflict if possible to do so `These steps will help rule out a possible plugin conflict.
1. Disable all the other third-party plugins and check whether that
solves the issue
2. If that solves the issue, please activate the plugins one by one to
rule out the conflicting plugin
3. If that doesn’t work, please check it by activating the parent theme
4. If the issue still persists, please activate a WordPress default
theme like Twenty Twenty and check`
Let us know if this fixes the issue or not.
Thank you