If the Send optional diagnostic data is not turning off, there could be an organizational level configuration at play here.

Windows 11 collects a significant amount of data, which might be a concern for those who value their privacy. Some data collection is necessary, such as information about your device model, hardware ...

In another attempt to give Windows 10 users more control over their data, Microsoft is making a few changes to its Settings app and Group Policy settings in the latest Windows 10 preview build (19577) ...