javascript - mapbox pins do not load all the time from geojson -

i have weird issue on mapbox js. loading in geojson files pins, works fine of time no errors. every json not seem load , no pins appear.

does not seem browser specific problem, or cache or cross domain (as same server , never work).

guessing in our geojson or js, never ever work.

our next step add callback , try loop again, wondering if there simple overlooking in way map box , geojson play together?

so turns out issue here having series of objects on map within map box (a pin, drawn boxes). load in geojson.

so loading not issue, adding layer being flatly ignored.