ISPConfig Letsencrypt SSL certificate not working from admin webinterface

I am running ISPConfig Version: 3.3.0p2 on top of a Ubuntu linux. And setting up a website with letsencrypt was not a issue before. I want to setup a new site and now it has become an issue:
- I can check the boxes and press the save button
- I see that it is working
- But there's no result at all, both checkboxes are clear and my server is not responding the way I like it to respond

Is there anybody who has any clue ? and can help me out with this