The problem is with the time, I manually fixed the time by writing `date -s "..." `. After that everything worked as intended. Now I'm wondering why the NTP is not setting the time properly and every time I start the system, the date is at "2019-04-11 19:28:42".
After trying some different solutions , I managed to solve the problem by the following way: I just turned off the WiFi in the Kodi settings menu and I just connected my PI 4 and the router with an Ethernet Cable. This solved the issue and the time was correctly updated. I'm not sure why it didn't work with WiFi before.