Redirected non-existing pages going home instead 404

What is wrong:
Some part of this main redirect is causing that every non-existing page inside mysite.com (This site is empty) is redirected to the main page which is in the subdomain mysite.com/es/ instead of getting a 404 error.

My redirect in the htaccess file:

Main Redirect

RewriteEngine On
RewriteCond %{HTTP_HOST} ^mysite\.com$ [OR]
RewriteCond %{HTTP_HOST} ^www\.mysite\.com$
RewriteRule ^/?$ "https\:\/\/mysite\.com\/es\/" [R=301,L]

RewriteCond %{HTTP_HOST} ^mysite\.com$ [OR]
RewriteCond %{HTTP_HOST} ^www\.mysite\.com$
RewriteRule ^index\.html$ "https\:\/\/mysite\.com\/es\/" [R=301,L]

RewriteCond %{HTTP_HOST} ^mysite\.com$ [OR]
RewriteCond %{HTTP_HOST} ^www\.mysite\.com$
RewriteRule ^indexingles\.html$ "https\:\/\/mysite\.com\/en\/" [R=301,L]

Works perfect for the following:
Is perfect that mysite.com/ redirects => mysite.com/es
Is perfect that index.html redirects => mysite.com/es
Is perfect that indexingles.html redirects => mysite.com/en

Summarizing

Every URL that has mysite.com/non-existen-page redirects to the main page: mysite.com/es/. Its a very bad thing that it doesn’t get a 404 error. I have to change this and I don’t know how .

If the URL is mysite.com/es/non-existen-page it gets a 404 error which is ok.

If the URL is mysite.com/en/non-existen-page it gets a 404 error which is ok.