Troubles with LRGB composition

Hi everybody! I am familiarizing with LRGB composition following tutorials, however I got bad results. I present here my job om Cocoon Nebula for your comments and advices. I created final stacked images from L,R,G,B channels by using sirilic scritp (I tried also with manual processing, with same results), and each on these looks to me good, with a lot of details, however when I use RGB Composition Tool it is very hard to elaborate, many details are lost and a lot of noise arise!
Here I attach pictures of stacked image L with limited post-processing and a starless version (I think both are good!), and a starless version of LRGB composition…
Please, let me know where I am wrong…
Thank you,

Hello and welcome!
For LRGB, pre-stretching images is usually required.
If you haven’t seen this already, it will probably answer most of your questions: Siril - RGB composition