@nexxai I understood the problem... and frankly, I consider it a "nuisance" because in my local environment (Docker - Sail), this issue didn't arise, whereas when deploying the application to a Plesk server or a LEMP server in the production environment, I'm not sure why it occurred (and I would really like to understand).
In any case, the problem was due to the capitalization in the component name.
It seems absurd to me, but by renaming:
app/View/Components/sidebarnominativi.php to app/View/Components/SidebarNominativi.php
and
resources/views/components/sidebarNominativi.blade.php to resources/views/components/SidebarNominativi.blade.php
Everything works... simple as that.
So, when I run the command:
php artisan make:component Sidebar
I need to remember to use the first letter capitalized... I find it strange, frankly. But since it works, I'll do it.
In my local environment (deployed following https://laravel.com/docs/11.x/installation#sail-on-windows), everything works perfectly without this precaution.
However, when I brought the project to Plesk or a LEMP server and deployed it there... boom, the component controllers were ignored, and "undefined variable" errors started popping up.
Are there any server-side settings that can be modified to avoid this behavior, or is there a logic behind it that I'm missing?
I can't find any references about this in the documentation.