Can't change tracks from stereo balanced to stereo combined panning

I really hope someone can help me with this! In my template, I had all my tracks set to stereo combined panning. Today, I opened it up and a whole bunch of them were changed to stereo balanced panning, panned 100% to the left. However the audio from these tracks is still coming out centered. If I center the panning, it pans to the right about 50%. I can’t change it back to stereo combined panning. The little dropdown arrow doesn’t appear.

This happened to about 25% of the tracks in my rather large template. How did this happen? How can I fix it? Please, have mercy, help me!

All tracks and groups in my template are stereo. I’m using Cubase 10.5.