No DHCP server was found / connected no internet / connection failure

WiFi has been a bit temperamental before, but usually I restart the router and it fixes itself. I've tried restarting the router 5 times with no luck.

I'm wondering if my router is the issue, because I cannot connect to the internet on any of my devices (giving similar errors usually at the finding IP address stage). But the other flats in my building are not experiencing a problem I don't think.

Anything I can try? Thanks!