Example this…
a sphere as Flip Fluid from Object (with a Y position of 2)
a grid as a Static Object below with volume collision turned off.
the DopNet's flip fluid object is set to
particle separation 0.025 and radius scale 0.5

Frame 1 over 250,000 points
Frame 20 about half way collided has evaporated to under 60,000 points
Frame 40 below 5,000 points

So 98.8% of the fluid points have somehow evaporated upon collision with a simple grid <fact>.

My simple questions are…
How did that happen?
and
How can I stop flip fluids from evaporating seemingly illogically?

Hard to guess without .hip
Do you have Closed Boundaries of Flip Object turned on.

Thank you for an attempt to help understand this.

PradeepBarua
Hard to guess without .hip
Do you have Closed Boundaries of Flip Object turned on.

It's so simple I didn't think you would need one. (I would have added changes needed from the defaults to describe steps to reproduce otherwise.)
I stripped it down to the bare essence once I realized it is in complete violation of the very physics it's suppose to be simulating.
Any change of a Flip Fluid Objects Geometry's point count by even 1 point is in complete violation.

Boundaries makes no difference. The default is off.
Your other thought is unclear I've described it as a FLIP Fluid from Object?! In the AutoDopNetwork generated it has a FlipSolver and a FlipFluidObject with default settings other then as described (only to enhance the effect with more production like settings).

For clarity it's a middle click on the FlipFluidObject to inspect the oddly shrinking Geometry's Point count.

Hunt down Reseeding and turn it off - search for it in the manual.

As a side note - if you get into computational physics, you'll see you must make approximations on the ‘real world’ otherwise it the computer will process for ever and produce nothing of use

Yes okay thanks!
AutoDopNetwork FlipSolver1 <TAB>ParticleMotion <SubTAB> Reseeding Particles DISABLED

/obj/AutoDopNetwork/flipsolver1/reseed

Seems that is what made almost all the particles disappear on collision.
Now a particle is a particle and not part of some default Quantum delusion.

MartybNz
Hunt down Reseeding and turn it off - search for it in the manual.