Multitrack changed from stereo to mono without user input

Hi everyone,

I've been editing a short film in Audition that was set up as a 32 bit/48khz stereo multitrack that was imported through a .xml. I've been editing in stereo, no changes to audio hardware or channel mapping, and have used both track and clip pans in the last week. I left it for a few days and opened it up to do a final pass and noticed that it's now a mono session with only the clips that I've panned individually showing the pan keyframes. All the track pans have disappeared. I've made a copy (through windows explorer) of the .sesx file and opened it in notepad, and both the session and the master track are stereo.

When I play the section with the individually panned clips, the meters show that each output channel are panning, but the options to change on other clips and the tracks aren’t there. All my bus tracks were setup stereo, as were majority of the tracks.

I've also screenshots of the master track, a section of clips that have been individually panned, and the top of the .sesx opened in notepad.

Thanks in advance!