Your model is still showing the original dimensions in mm.
I don’t see where you have ‘scaled up’.
Try using the Dave Method (search for it in this forum).
PS. And your cylinder isn’t a solid - just a Group. Solid Inspector says you have two stray edges and an external face. Solid inspector offers to fix all, and when I’ve done that, the cylinder becomes a solid group.
But it still has too many edges to cut cleanly. This is the result from Eneroth’s Solid Tools, even on the 1000x times scaled up model.
You could clean this up, but it would be easier to remake the cylinder with fewer edges in the circle you start from.
Tried that with a 24 side cylinder instead of 96. Cuts the edges cleanly this time, but doesn’t make a surface round the hole in the funnel.
You could try stitching this one together.
But it might be easier to remake the funnel with fewer faces too - there are a LOT as View/Hidden Geometry shows:
