Hi @valepouf9
I hope you are doing well today.
I made a test on my lab site with free version of Visual Composer and I was able to add Forminator shortcode via HTML module from Visual Composer without any kind of issue. Please note there is no integration between Visual Composer and Forminator so in edit mode you will see only shortcode. As for preview mode I can see my form fully.
In forms, appear that i have 4 forms but dont let me acces any of them. Is this because by the builder im using?
This issue could be a plugin conflict. Would you please run a conflict test? Please deactivate all plugins except Forminator and check if the problem is gone. If so, then enable all plugins one by one and find which one is having a conflict. If there is no positive result, switch to the default WordPress theme like 2019, and see if it works.
Before this test, we recommend full site backup or running this test on the staging site.
Kind Regards,
Kris