The device has an IP address and is able to resolve the IP of the server but it’s showing HTTP status code 0, which isn’t a valid one.
Either a firewall is blocking the requests or there’s an IP conflict or a rogue DHCP that’s providing a bad gateway IP.
You could try adding a static entry to the ARP table but then we’re getting ourselves in some other mess.
Do you happen to be using a (misconfigured) powerline adapter? Multiple routers in the network?

If the following returns more than one result, then you’ve most likely found your cause.
nmap --script broadcast-dhcp-discover

I may of course be wrong.