Read only on my user's folder -> Firefox can't save history

My user's folder (c:\users\my_user) is always readonly. When I unset
Read Only (right-click, properties, uncheck ReadOnly, apply to all
folders and subfolders), the next time I verify about the readonly,
it's back.
Well, I still can put pictures in my Pictures folder, but the real
problem for me is that c:\users\my_user\appdata\local\mozilla and
c:\users\my_user\appdata\roaming\mozilla folders are always read only,
even after unchecking it. So due to this, Mozilla Firefox can't save
its history, where I went, so I always have to retype the url or use
favorites to go to websites I go many times a day if I closed Firefox
at any moment.

Where might be the setting that makes users folders read only?
I've tried to add Full control and ownership on my user folder for my
user account, but the problem is still the same.

Thanks

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cf