Unable to start listening on the UDP port

[c15412]

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Previously, both UDP and TCP ports were listening simultaneously, but now only TCP is listening, and UDP is not, which prevents RTSP from working.
After multiple attempts confirmed: Every time the RTSP handshake begins, the Sunshine process disappears and is then restarted by the service (and the logs are overwritten during the restart). (I could see the process PID change in Task Manager, so I concluded that the process was restarted.)

(I am not a native English speaker, so I’m using a translation tool.
I can only guarantee the general meaning.
if you need more details, I’d be happy to help.)

Here are some logs I may have captured that might be useful:
sunshine-2026-07-31-23-14-utc+8.txt

[darksidewalker]

Steamlink (steam client) seem to use the same port.

Closing steam resolves the error. But that's no option for gaming.

Workaround running sunshine first than steam (optional disable remoteplay from steam).

[c15412]

Steamlink (steam client) seem to use the same port.

Closing steam resolves the error. But that's no option for gaming.

Workaround running sunshine first than steam (optional disable remoteplay from steam).

I tried it, but it didn't work. I didn't even have Steam running; I set Sunshine to start automatically at boot, but it still didn't work. Also, when I checked the listening status, I saw that the port wasn't in use.

[c15412]

Steamlink (steam client) seem to use the same port.

Closing steam resolves the error. But that's no option for gaming.

Workaround running sunshine first than steam (optional disable remoteplay from steam).

However, you're on the right idea.
I found that the system's winnat service had pre-reserved UDP ports
(the command netsh interface ipv4 show excludedportrange protocol=udp shows that ports 47976–48075 are excluded by the system, meaning they are in use).
After stopping the service and manually adding the port exclusions, everything seems to be working normally now.