this solved my problem

not sure if its a bad idea or not but it works

RewriteEngine On

 RewriteCond %{REQUEST_URI} ^/admin
 RewriteRule ^ index.php [L]

# Redirect Trailing Slashes...
RewriteRule ^(.*)/$ /$1 [L,R=301]

# Handle Front Controller...
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^ index.php [L]

Your route should not be broken. Routes are used only when the file exists in the public folder.

EDIT Im wrong :) it checks for the folder too. Anyway that would be better that you rename your files or your admin route than hacking the .htaccess. In the long run it will be better to stick to the conventions. Just my opinion. :)

The route is not called since apache tries to give me the folder/file named exactly the same as my route (in public folder).

i just added an extra bit of code in .htaccess before checking if the request matches a directory or a file and solved this.

a bit hacky solution but works

If nothing else, the fact that changing one folder in your public directory would require hundreds of separate changes means you have good idea of a place to refactor. ;)