Weird rendering issue using Niagara + 2D Offset Refraction

Hey there, I am wondering if 2D Offset refraction has any kind of limitations when is about using it with Niagara. I am currently setting up a jet of fire but the refraction seems to look wrong at the very first frame of the lifetime of the particle.

The first screenshot shows just how the fire + refraction is supposed to look. The two fire jets on the left are part of the Niagara System and the fire jet on the right is a static mesh, using the same material instance than the Niagara System:

Next Screenshot is what I see at the very first frame for the Niagara Systems and I don´t understand why. Both the Niagara System and the Static Mesh are using exactly the same material instance, but the issue just appears on the Niagara Particles:

I have tried setting the refraction to 0 (in 2D Offset seems to be the way rather than 1) and also tried to completely disconnect the input from the Refraction Pin…but the issue still persists. This is what the description on the material says about the Refraction Method for 2D Offset + an screenshot of the preview in the material:


So I am not quite sure how to proceed here. The way I understand this is that I shouldn´t see any refraction at all if nothing is connected to the refraction pin, am I right? Also I don’t understand why the particles show that crazy refraction value at the very first frame of the sim.

Is this an issue on my own or is there something else going on here? Any tips or advices would be hugely appreciate it.