Okay, so it seems like the game is confusing which of the bags is "full" and which is "empty" - but that's my best guess, as after I re-filled the "empty" bags, everything seems like it went back to normal.
Not sure if the game is having a problem with identifying the bags that are full, or if trash from inside of the bags is being deleted, or what.
Anyway, thanks for the work you guys have been putting into it. I've put upwards of 500 hours into this game, now, and I doubt I'll stop any time soon.