Private History and Cookies remain forever.
I open a new private window, go to a website such as Wikipedia, and use the in site search bar to search for say "dogs". Then close all private windows and all other Firefox windows, and re open a new regular Firefox window, both my search for "Wikipedia" is remembered by the search bar, and my search for "dogs" is remembered by Wikipedia. Clearing my cookies and deleting my browsing history does nothing to fix this. Reinstalling Firefox has also done nothing to fix this. Every bit of information i can find on the topic says Firefox's private browsing mode deletes cookies and history upon closing all windows, but this is not the case for me. My temporary patch is to remove all address bar suggestions from everywhere, but i only want private browsing mode to function as intended. Thank you for reading all this and i hope you can assist.