uMatrix 1.4.0
                 Canvasblocker 0.5.14.

              Widevine Content Decryption Module provided by Google Inc. Version 4.10.1440.19

Basically I have Never Remember History enabled, and each time I open FF there's data in 'Cookies and Site Data'. Under 'Cookies and Site Data' it will say there's a bit of data (in the photo is says 16Kb, which is pretty typical). If I look under 'manage cookies and site data' there will be nothing there. Sometimes the cookies or cache or whatever is bigger if the last time I used that profile I was watching videos, at most it will be a couple Mb's maybe. If I wipe it out, it will go to 0Kb, and then for the rest of the profile session, even if I have a bazillion tabs open, it will say 0, but then there's always a cache there the next time I start that profile. What is it? Why is there always a small amount of data in the 'Cookies and Site Data' section each time I restart a profile? I'm currently running version 68.2.0esr on Debian Linux version 5.3.0-1-amd64. Extension: uBlock Origin 1.23.0 uMatrix 1.4.0 Canvasblocker 0.5.14. Plugins: OpenH264 Video Codec provided by Cisco Systems, Inc. (disabled) Version 1.8.1.1 Widevine Content Decryption Module provided by Google Inc. Version 4.10.1440.19 I have web history turned off ('Never Remember History'), trackers blocked, cookies enabled w/ third party disabled, auto search engine update turned on, Do Not Track enabled, 'Delete cookies and site data when Firefox is closed' enabled by default (b/c history is off). I might have changed a few tiny things in about:config but nothing I remember offhand. Any other system info I can look up in need be.