Observed Results: Safari Preferences - selecting Privacy - Cookies and Website data defaults as unchecked. Upon checking this option I COULD NOT logon to any secure Apple site. Developer, AppleID When turned off everything works normal.
If you get on (when the box is /NOT checked) and then CHECKED the option while logged on to these sites selecting LOG OFF will NOT WORK any you stay at the same please as you were when you tried to log in.
Then again unchecking the box allows for normal operations.
Reported to Apple
MANAGE WEBSITE DATA ,selecting ALL to erase does nothing.
Reported to Apple