Lost wax casting non fills

Hello,

I am new to lost wax casting and had an unsuccessful first casting. Maybe someone could help me out with identifying my errors.

I built a little wax tree with wax injected earrings, charm and hand carved rings, burnt them out in a 3.15" x 4" perforated flask, in a paragon E12 kiln for 12 hours (started at 300F - 400F - 700F - 1350F - 1130F Casting temp i held for more than 2 hours)
I used a KAYA cast for vacuum chamber casting, melted sterling silver until 1850F in an electric furnace and poured it in my mold. After 5 min I quenched my flask and unfortunately just one charm made it completely. the bear charm was on the very top of the tree and the heaviest model. the top pair of earrings just filled half and the lower placed earrings stopped right at the sprues, same for the basic rings at the bottom of the wax tree.

see attached pictures of the final tree and also the wax tree.

My guess would be that my sprues are too skinny? but they were like 3 mm which I though would be fine, also for the lower earrings I had 4 sprues attached the the inside of the earring to ensure the metal reaches the whole model.

Thanks for your help, really appreciate it!
Raffaela