It sounds like you have a disorganized network, where all devices are DHCP.
The best approach is to set up your networking, so that your appliance devices, such as the streaming server, printers, smart devices etc, are statically assigned. Either manually or through 'IP Address Reservation' in the router. That a way the appliance always has the same network destination.
This looks like the server was powered down, and some other device connected to the network, and the router assigned that device the IP address and when the server or router was powered back on, it assigned it a different IP address.