Firefox Support Forum

I have used firefox for years as my browser with my home page set to google. I have always had a bookmarks toolbar but never a bookmarks side bar and do not want one. The other day a bookmarks side bar suddenly appeared. I have moved it from left side to right side and can delete it temporarily by using CTRL +B, but can't find a way to permanently remove it, i.e. make the default setting so that the side bar doesn't appear. can you help?

I had downloaded a couple of pdfs from google drive via private browsing which were stored in my 'Downloads' folder. But as soon as I closed the window the pdfs were deleted. I had also downloaded a zip file which wasn't deleted.