Motif stores the mix in the following situations:

- Entering utility mode
- Pressing REC
- Using Event edit
- Using a Song/Pattern Job

Since the mix settings can be affected by sequencer playback, they often change during a Song/Pattern, then when you do any of the above commands, Motif stores the edited mix as part of the Song/Pattern.

Say you recorded some pan & filter sweeps at measures 15-20 of a sequence, play it back and the mix will change, stop the sequencer at measure 17 and record a few more notes, and Motif will store the mix with the values of pan/filter that were only meant to be at measure 17. Next time you load/play the song, the filter/pan will be wrong at the start.

To get back the original mix you have to have made a template to restore from.