I found a solution that works.
But I dont know exactly if it is the correct solution, or just a workaround. Maybe I just skipped something… or maybe its something not considered by Unity devs on the Trails module for the particle system (a sorting order for the particle and another for the trail, not both togheter). I dont know.
But I changed the **“Render Queue” and added +1 on the material ** for ‘ParticleStar’ (as shown on the picture above) and it works. I might mess up something later on, but for now it does what I want.