Hi...I am on Win 10 and solved a similar problem after encountering this issue when my PC started connecting to my network through a wifi bridge. I think this solution should work for most situations, though it takes a few steps...
At your router, assign a static IP address to each of your airplay devices.
Then in TuneBlade, manually add those IP addresses as AirPlay devices. TuneBlade needs a port number. The default port for Airplay is 5000.
If you have multiple airplay devices at a single IP address, you can play around with the port numbers (I think they get chosen sequentially starting with 5000; so with 2 devices, the first will be on port 5000 and the second on 5001).