I am using Firefox 96.0.1 on macOS Monterey 12.1 If you have "'Delete cookies and site data when Firefox is closed''' checked in Privacy & Security/Cookies and Site Data then this causes sites that use a service worker to fail registration with the error: "Failed to register/update a ServiceWorker for scope https://every-layout.dev/: Storage access is restricted in this context due to user settings or private browsing mode." This *only* occurs with Firefox, Safari, Chrome, Brave etc. all register the service worker OK. I know the workaround is to put in an Exception to Allow but this should not be necessary. In this case the service worker is use to provide access to paid for content and off-line reading. I contacted the site's developers and they tell me that they have been waiting for ages for Mozilla to fix this issue and suggested I used an alternative browser. Can anyone explain why Firefox behaves in this way and if this "feature" will be fixed on future releases? Thanks John