Content-Security-Policy: The page’s settings blocked the loading of a resource at blob: (“default-src”).

We are using AWS chat in our application. when i am trying to download transcript from the firefox browser getting bellow Error.
Content-Security-Policy: The page’s settings blocked the loading of a resource at blob:https://website address (“default-src”).

Note: I have tried adding "blob:" inside default-src - self and I have attached the image for the same.