Dotenv plugin does not work with private plugin

### MAIN ERROR MESSAGE ###
Whoops \ Exception \ ErrorException (E_WARNING)
Undefined array key "session_ss"





### ERROR LOG ###
20
Whoops\Exception\ErrorException
…/user/plugins/private/private.php242
19
Grav\Common\Debugger deprecatedErrorHandler
…/user/plugins/private/private.php242
18
Grav\Plugin\PrivatePlugin isConnected
…/user/plugins/private/private.php50
17
Grav\Plugin\PrivatePlugin onPluginsInitialized
…/vendor/symfony/event-dispatcher/EventDispatcher.php264
16
Symfony\Component\EventDispatcher\EventDispatcher doDispatch
…/vendor/symfony/event-dispatcher/EventDispatcher.php239
15
Symfony\Component\EventDispatcher\EventDispatcher callListeners
…/vendor/symfony/event-dispatcher/EventDispatcher.php73
14
Symfony\Component\EventDispatcher\EventDispatcher dispatch
…/system/src/Grav/Common/Grav.php597
13
Grav\Common\Grav fireEvent
…/system/src/Grav/Common/Processors/PluginsProcessor.php36
12
Grav\Common\Processors\PluginsProcessor process
…/system/src/Grav/Framework/RequestHandler/Traits/RequestHandlerTrait.php50
11
Grav\Framework\RequestHandler\RequestHandler handle
…/system/src/Grav/Framework/RequestHandler/Traits/RequestHandlerTrait.php62
10
Grav\Framework\RequestHandler\RequestHandler handle
…/system/src/Grav/Common/Processors/InitializeProcessor.php130
9
Grav\Common\Processors\InitializeProcessor Grav\Common\Processors\{closure}
…/system/src/Grav/Common/Debugger.php546
8
Grav\Common\Debugger profile
…/system/src/Grav/Common/Processors/InitializeProcessor.php129
7
Grav\Common\Processors\InitializeProcessor process
…/system/src/Grav/Framework/RequestHandler/Traits/RequestHandlerTrait.php50
6
Grav\Framework\RequestHandler\RequestHandler handle
…/system/src/Grav/Framework/RequestHandler/Traits/RequestHandlerTrait.php62
5
Grav\Framework\RequestHandler\RequestHandler handle
…/system/src/Grav/Framework/RequestHandler/Middlewares/MultipartRequestSupport.php40
4
Grav\Framework\RequestHandler\Middlewares\MultipartRequestSupport process
…/system/src/Grav/Framework/RequestHandler/Traits/RequestHandlerTrait.php50
3
Grav\Framework\RequestHandler\RequestHandler handle
…/system/src/Grav/Framework/RequestHandler/Traits/RequestHandlerTrait.php62
2
Grav\Framework\RequestHandler\RequestHandler handle
…/system/src/Grav/Common/Grav.php312
1
Grav\Common\Grav process
…/index.php47
0
 require
…/system/router.php55
/home/chraebsli/_work/akkordeonsolothurn.ch/user/plugins/private/private.php





 ### CODE SNIPPET OF ERROR ###
    protected function isConnected()
    {
    	### THIS LINE CAUSES THE ERROR ###
        if (isset($_SESSION[$this->privateconf['session_ss']]) && $_SESSION[$this->privateconf['session_ss']] == sha1($_SESSION['username'])){
            return true;
        } else {
            return false;
        }
    }



}






### ENVIRONMENT ###
Environment & details:
GET Data empty
POST Data empty
Files empty
Cookies empty
Session empty
Server/Request Data
DOCUMENT_ROOT
"/home/chraebsli/_work/akkordeonsolothurn.ch"
REMOTE_ADDR
"127.0.0.1"
REMOTE_PORT
"51324"
SERVER_SOFTWARE
"PHP/8.3.3 (Development Server)"
SERVER_PROTOCOL
"HTTP/1.1"
SERVER_NAME
"127.0.0.1"
SERVER_PORT
"8000"
REQUEST_URI
"/"
REQUEST_METHOD
"GET"
SCRIPT_NAME
"/index.php"
SCRIPT_FILENAME
"/home/chraebsli/_work/akkordeonsolothurn.ch/index.php"
PHP_SELF
"/index.php"
HTTP_HOST
"127.0.0.1:8000"
HTTP_CONNECTION
"keep-alive"
HTTP_SEC_CH_UA
""Brave";v="123", "Not:A-Brand";v="8", "Chromium";v="123""
HTTP_SEC_CH_UA_MOBILE
"?0"
HTTP_SEC_CH_UA_PLATFORM
""Linux""
HTTP_UPGRADE_INSECURE_REQUESTS
"1"
HTTP_USER_AGENT
"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36"
HTTP_ACCEPT
"text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8"
HTTP_SEC_GPC
"1"
HTTP_SEC_FETCH_SITE
"none"
HTTP_SEC_FETCH_MODE
"navigate"
HTTP_SEC_FETCH_USER
"?1"
HTTP_SEC_FETCH_DEST
"document"
HTTP_ACCEPT_ENCODING
"gzip, deflate, br, zstd"
HTTP_ACCEPT_LANGUAGE
"de-CH,de;q=0.9,en;q=0.8"
REQUEST_TIME_FLOAT
1713447177.019
REQUEST_TIME
1713447177
PHP_CLI_ROUTER
true
plugins.private.users.no_user
"ad0b81db97b474ea668c0b42dac614f3fa183894"
plugins.email_DASH_sendgrid.api_key
"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"
Environment Variables
plugins.private.users.no_user
"ad0b81db97b474ea668c0b42dac614f3fa183894"
plugins.email_DASH_sendgrid.api_key
"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"
Registered Handlers
0. Whoops\Handler\PrettyPageHandler
1. Whoops\Handler\CallbackHandler