Last night I received a shiny Spiritomb from a friend (which is
also the featured shiny plushie atm) and since then the progress
bar is having a negative amount of Dream Points spent. Maybe the
plushie I received did count for the progress bar and for that
reason decreased with a certain amount of points?
Every plushie I'd send right now wouldn't count for the bar
progress but only to get it to the (normal) zero point first.