It seems to only happen on my android devices and my new macbook. I can access via ip address, but that is frustrating because unmenu uses the hostname for all links. I read somewhere that it has something to do with "search domains", but I have no idea what my domain is. Anyway i can remove this requirement or do I need to dig into router/unraid configuration?

I thought setting a domain in my dd-wrt settings (tried 'intranet.local') would fix the issue, but that is a no go. I tried access via http://fileserver.intranet.local to nothing.

Set ip address reservations in dhcp with hostname, e.g., tower. Make sure that local hostnames are used. This may be the default.