Angular UI router loads wrong controller/template

Question

Maybe it's something simple, but this is the first time I'm using the angular-ui-router. I'm using html5 mode and I've got the following states configured:

    $locationProvider.html5Mode(true);

    $authProvider.loginUrl = API_LOCATION + 'authenticate';

    $urlRouterProvider.otherwise('/auth');
    
    $stateProvider
        .state('auth', {
            url: '/auth',
            templateUrl: TEMPLATES_LOCATION + 'login.html',
            controller: 'AuthController as auth'
        })
        .state('country', {
            url: '/country',
            templateUrl: TEMPLATES_LOCATION + 'country.index.html',
            controller: 'CountryListController'
        })
        .state('country.select', {
            url: '/select',
            templateUrl: TEMPLATES_LOCATION + 'country.select.html',
            controller: 'CountrySelectController'
        })
        .state('country.edit', {
            url: '/:isoCode',
            templateUrl: TEMPLATES_LOCATION + 'country.edit.html',
            controller: 'CountryEditController'
        });

All country routes load country.index.html and CountryEditController. Why?

EDIT

my .htaccess file (the angular app is in a subfolder named "admin")

RewriteEngine on

#RewriteBase /admin/ <- tried this too

RewriteCond %{HTTP:Authorization} ^(.*)
RewriteRule .* - [e=HTTP_AUTHORIZATION:%1]

RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]

RewriteRule ^(.*) /admin/index.html [NC,L]