OBS fails to connect after update to 30.2.3

[theFireProject]

Operating System Info	Windows 11
Other OS	No response
OBS Studio Version	31.0.0
OBS Studio Version (Other)	No response
OBS Studio Log URL	https://obsproject.com/logs/Rm7f7fgSmXiFhc3E
OBS Studio Crash Log URL	No response

Expected Behavior

OBS should connect to the RTMP server like it does in version 30.0.2 (see https://obsproject.com/logs/esWxEHvkqYM4krtQ).

Current Behavior

OBS fails to connect to the server.

Steps to Reproduce

1. Run ffplay -listen 1 -i rtmp://localhost:1935/live
2. Start OBS
3. Start streaming

[alinsavix]

02:12:18.564: localhost:1935/live is offline. Try a different server (ECONNREFUSED).

This seems to me to be a problem outside of OBS; ECONNREFUSED is the error code produced when nothing is listening on the port being connected to.

[theFireProject]

If this is not an issue with OBS, why does version 30.0.2 connect successfully and 31.0.0 does not? I have downloaded both OBS zip files and both versions are using exactly the same profile and settings located under %APPDATA%\obs-studio.

I have also tested other OBS versions. Up to version 30.2.2 everything works fine, but from version 30.2.3 OBS fails to connect. There were some changes to RTMP connection in this version:

30.2.3 Hotfix Changes

• Fixed a possible crash when connecting to an RTMP server [notr1ch]
• Fixed a possible RTMP disconnect/timeout on Windows systems without IPv6 connectivity when connecting to a dual-stack RTMP server [notr1ch]

^{https://github.com/obsproject/obs-studio/releases/tag/30.2.3}

So I think there's a bug with IPv6 in v30.2.3 because...

1. If I start the RTMP server on rtmp://localhost:1935, it's accessible under localhost and ::1 but it's not available under 127.0.0.1. So I assume that the server uses an IPv6 address. When I do ping localhost I can also see that localhost resolves to the IPv6 address ::1. In this case I cannot connect to the server with OBS 30.2.3.

2. If I start the RTMP server on rtmp://127.0.0.1:1935, it's accessible under localhost and 127.0.0.1 but it's not available under ::1. In this case it uses an IPv4 address and I can connect to the server in both versions of OBS.

So the old version 30.2.2 manages to connect to both the IPv4 and IPv6 address when you enter localhost while the new version of OBS can only connect to the IPv4 address when you enter localhost.

I think the reason for this might be the commit 4213643 in the changes from 30.2.2...30.2.3.