Strange invisible line dividing inside of object in fluid simulation

I’m getting this weird invisible line in the middle of my object in when doing a fluid simulation:

I’ve checked that normals are flipped, and recalculated them all to the inside. It seems to be something normals related because when I flip them the fluid falls down that path and skips everything else, but after closely inspecting the normals I can’t figure out why that would be… there don’t even appear to be any normals that directly correlate with the line.

Any idea what could be going on here?

Blender file here:

fluidfunnel2c.blend (3.0 MB)