I am sorry but I could not understand. If you disallow permissions, it will disable rating quiz option for users. If you want to completely disable rating feature, you need to disable the Enable Ratings option.
The rating permission will disable rating functionality when taking quiz. "Enable Ratings" option will be used to control rating shown on listing pages.
If these two options are not working, that means either you have some template override or some other issue. Can you please send me your website details using contact us form so that I can check the issue?
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