My internet protocol is never saved, then everything is gone and I have to re-enter everything. What can I do there?

That's why I don't have Wi-Fi either and the laptop is unusable again.

Why don't you use DHCP?

Look at my other question.
Yes, I don't know, it always goes out. Now DHCP is activated again in the WLAN.

Let your computer always get the IP address automatically, then you don't have to change anything.

Why did you change that?