i added css on my website. One is bootstrap and one is a custom css.
I addedd it on my Magento_Theme folder (inside layout/default_head_block.xml)

    <css src="css/bootstrap/css/bootstrap.css" order="100" />
    <css src="css/reflexmania2-custom.css" order="100" />     

suddendly there was a problem on these css. They are not loaded in the frontend css inside the HEAD tag.

i tried cleaning cache, generated folders, view_preprocessed and then running
 
    setup:upgrade
    setup:di:compile
    setup:static-content:deploy 

but nothing. they are not loaded.

they are compiled because i can see inside my pub/static folder.

i'm getting crazy. How can i solve this problem?

Thanks for help