How to fill with fluid a deforming and growing geometry

[anbt]

Hello guys,

I am desperate on this one!
I want to fill with water this evolving shape that starts from nothing and expand like a flower.

The idea is to make the fluid squirt out of it from the top (there is a hole on the top of the geo) but to start, I was thinking of filling the geo first. Maybe there are other ways to get the squirt going but I would like to fill the shape with liquid first. 

I am aware that I should use deforming VDB object for collision, I know the workflow but there is definitely something I don't know here. Whatever I do, the liquid goes through. I tried with a super high res VDB or even 8 substeps, nothing works.

I suppose it will be easier if I attach the file so here it is

test_ffluid_inside_growing_geo.hip

Any idea?

Thank you very much

[anbt]

so now, I fixed one problem, but I get a new one in return for free 

I made my collision volume way thicker, which I didn't want to because I can't get a nice liquid filling closely along the inside surface but at least, it fills up the inside until a certain frame, and then, it suddenly stops.

I noticed by visualising collisions in the flip object (the stuff in purple) that my collision area reverses itself at a specific time (it kind of inverts the sign of the SDF. I mean not kinda, this is what happens!)
I figured out it comes from my shape which starts as a closed shape (a hollow shape but closed), and then it opens from the top. And it is at that specific moment my liquid starts to act weird. It doesn't fill, and it gets extremely slow.

Any idea how to fix this? So far, I managed to fix everything but now, it starts to get too tricky and I am sure the answer will be a line of Vex to tell my volume to not inverse itself at the specific frame but I don't know how to do this.

Or is it something else?

Cheers!!