Failed funnel for dry&dry

I made a custom pour funnel for dry&dry silica gel to pour into this model (https://makerworld.com/en/models/85380#profileId-91273), but it failed and kept backing up in the funnel for some reason, even though the opening is about 10mm wide more than enough. I would appreciate it if someone could help me fix this since this is my first Fusion 360 model.