Hello Keith, thank you for your reply.
I have changed between static and DHCP multiple times using both routers, and on both versions 1.5.0 and 1.5.1, and before and after doing the hard reset.
Both routers are giving correct IP settings to my laptop when connected to the same port with the same cable, meaning DHCP is working as it should on the routers.
Static IP assignment should also work on these routers, but does not work for the SQ5.
As I mentioned this used to work on the exact same router last time I tried, about a month ago.
I also hooked it up to a third router, which I was using regularly in the past with the SQ5, and there was no network connection there either.
I suspect I need to get someone to take a look at it, unless there are other magic buttons to press to reset or get detailed diagnostics.