I did reboot my router. When it started again I found both of my WLANs set to off. It is obvious to me that I did not do that and in fact I cannot understand if this was the case how my second Samsung which does not have a SIM card in it for mobile data was connected to the Internet and I could access YouTube and watch videos. I have no other WiFi credentials than the ones of my WiFi in any of my devices (in my main home - my country home is 175km away and I am pretty sure the WiFi there is completely out of range). Now it seems to work. Maybe the bugs in the mind of the bugs was the problem and these must definitely be debugged.