Your symptoms sound like an IP conflict.
Try powering off every device with an IP address. Not just shut down, remove power. Then bring your network back up 1 item at a time, starting with the ISP modem, then your router, then the Unraid server, then start with one computer and see if you can manage the server again. If so, start bringing the other devices back online one at a time, and verify things are still working.
For wifi devices like phones and tablets, it should be sufficient to disable the wireless when you do the purge. When the wireless is reenabled they should get a new lease from the router.