PS4 always loses internet connection?

I have my PS4 connected via Wi-Fi to the Internet. The router is one of the latest Fritz boxes. At first everything worked out great. Then I turned off the PS4 and later I wanted to play again. Then suddenly it was there "Make an internet connection". If I now want to connect to the Internet via the network settings, it will only last forever and nothing will happen. As soon as I disconnect the router from the mains and reconnect again, the PS4 can usually reconnect to the internet. But when I turn it off again and then back on, there's exactly the same problem. That's really annoying. Does any of you know why that might be?

By the way, all other devices (mobile phones, televisions, etc.) are also connected to the Internet without problems and everything runs smoothly.

This is due to your provider, if your wireless network is not stable, he often loses the connection. This can be with a few seconds below and we usually do not even notice. The best way to circumvent the problem in which you ne ne LAN connection.

Too many devices are active in the house

But other devices never lose the connection, I would remember synonymous with the TV, if I watch movies, for example, or?

Have tried to disconnect all devices except the PS4, the problem was unfortunately still there.

Try changing your Nat type

Oh dear, unfortunately I'm not familiar with such things. But thanks anyway.