Webbuild and Android App does not connect to database directly

On my Website the user only can see the initial view. At the initial view some things are shown which are connected to the database. But if i try to use them, it does not work. I always get my error message.
Only if i login and dismiss the initial view, the things are working. Then if i logout and the initial view is back, everything is working too. But if i reload the Website, nothing is working at all until i had login one time. Same problem with the created Android App, it’s not connecting to the database directly. Only after i logged in first time, it works. No matter if i logout or not.
But also when i am logging in, i get the error message. (but nethertheless it’s logging in)

I hope it’s an internal error at your site. Do you have any ideas to solve this?
If it does not work my 30h of Website building weren’t useful.
What i also detected is that the websitename next to the Favicon is not the actual name. (I’ve changed it from Quiz to Quizzie, but it does not get refreshed. (I changed the name before launching the website)

You can see in the Video that every time at acting with the database there is an error.
And after the login some things are working.
(I’m sorry most things are german)

In the Android Preview Version everything works well. In Webpreview some things are not shown everytime at start (which are data from database)