Marker is not working

I have a multitrack where the marker is not working for whatever reason. I pressed M multiple times on the keyboard and I scrolled to 'edit' and 'cue marker', but it didn't work.  I also tried exiting the program and restarting it, but that didn't work. It does work on other multitracks, but not on this particular one.  I tried attaching my multitrack file here, but it didn't work.  Does anyone know what the problem could be?