Hello @Farid
Thank you for using Uni Education.
Regarding higher level of permission issue. Please make sure if your user level is administrator or superadmin in multisite or any plugin is creating such issue.
Please go to dashboard -> appearance -> customize -> additional css and add the following code.
.site-branding img.custom-logo { max-height: 200px; } //note: you can set the value you prefer.
Regards
Shark Themes