Well, being the only one in the house who can really solve computer problems:
We have a home nas in our network for filestorage and since a few weeks, we couldn't acces the device through windows explorer, so today I went on a exploration... First I tried the nas in a seperate different network, and it worked immediatly! oke great, try it in our main network again. And 'ofcours' it's not visible. So I go to the router webpage, and the page of our router just really sucks! So it was quite hard to find out if the NAS was attached or not, ad if so, under which IP. Finally found that, tried to connect to the webpage of the NAS, but got a timeout, ping would timeout too! I thought that that might have someting to do with that the NAS would connect via static IP. So I changed that to a dynamic IP, and I could atleast get to the website. After that I could try all the services and all of them worked perfectly, except for samba... And samba is the only service we actually use, so after that I thought that the device not showing up in network view in explorer had something to do with that the nas wouldn't show me a hostname in the router. So I tried to fix that, after an hour of trying to get the hostname to showup in the router, I just thought that I might try to connect to the nas via the IP. So I found via SO that I could just use //192.168.0.104 and I got into the samba server. So I guess that it was actually working all along 😒. After that I didn't want to bother to work with the hostnames, so I just gave the NAS a fixed IP, made a few shortcuts for my housemates and now it all works again.. For now at least...