Locale breaking due to adding speech marks

Recently migrated and updated a few of our company websites. One of our websites has sadly cannot create any posts due to some of the Locale being broken due to replacing apostrophe for speech marks breaking the JSON that is given to the page and causes the page to fail to display.

I’ve locally downloaded the full project and confirmed that all the locale files & even some CSS use ‘ but WordPress converts them to ” and breaks the JSON causing a dozen syntax errors then in JSON.

This has happened in both WordPress 5.9 & 6 (as we suspected updating may re-create the locale files)