I have this same issue, yet I'm not worried whatsoever. My 900 gram female het pied is currently going on 4 months of not eating. She's lost maybe 60 grams which is a large poop for her and she acts normal, husbandry has not changed.

She did this last year around 300 grams, then she goes on a huge streak of eating everything in site, then fasts again. I expect her to come around in the next month or 2 and we will be back to normal.