I've enabled "Delete cookies and site data when Firefox is closed" but while all cookies gets deleted, some random site data does not. Are my settings wrong, is this a bug, and what even is that data?
Additional Info: I use RFP, want to keep browsing history and site settings. Thank you very much.
That could simply be the cookies.txt file with no content whatsoever.
Firefox stores cookies in a DB file called cookies.sqlite, i just cleared cookies on a fresh new Firefox profile and the file is 524.3kB. A text dump of the file has four lines of text that describe the structure of the cookie database and that's it. No actual content.