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.
Oh, I get it now! In my sleep deprived state I missed that two of them had the same size. That seems like a reasonable guess, I'm just paranoid about cookies :P