Hi, I have a sidebar that appears to be permanent and I cannot make it go away. I opened firefox, went to reopen the previous session tab with control + shift + t, and my fingers slipped and hit the wrong combo of buttons. Then this thing appeared. This sidebar. I looked for similar questions on the topic, but it is not the history or bookmarks sidebar that pops up from control + h or control + b. I love hotkeys. So my question is, how do I disable the dang thing?? I tried going into custom tools, I tried looking into settings, but I really cannot find this. And it seems that other issues are usually to due with bookmarks/history sidebars - which I don't believe to be the issue here.. Any help is greatly appreciated! It's the sidebar on the left in my image if that provides any further info! Thanks :)