Navigation rail gone

The little lines on the right side of my chats are gone, so I can’t click through my old messages anymore. The ?message= trick was working until recently, but now that stopped too. Some of my writing conversations are really long, and I know what I’m looking for, so having to scroll through the whole chat is frustrating. I’ve already tried refreshing, hard refreshing, resetting my browser zoom, maximizing the window, and reopening the conversation. The lines still won’t show up.