localhost domain failure in sing-box 1.13.20 and newer

Operating system

Linux

System version

1.13.20

Installation type

Others

If you are using a graphical client, please provide the version of the client.

No response

Version

Description

I use sing-box in V2rayN in linux Ubuntu.

from sing-box 1.13.20 and next versions when "Enable TUN" is enabled, localhost domain shows "localhost didn’t send any data. ERR_EMPTY_RESPONSE"

older version were healthy about this.

Reproduction

Enable TUN in sing-box v1.13.20 or v1.13.21 and open a localhost domain. it shows "localhost didn’t send any data. ERR_EMPTY_RESPONSE"

Logs

Supporter

• I am a sponsor

Integrity requirements

• I confirm that I have read the documentation, understand the meaning of all the configuration items I wrote, and did not pile up seemingly useful options or default values.
• I confirm that I have provided the server and client configuration files and process that can be reproduced locally, instead of a complicated client configuration file that has been stripped of sensitive data.
• I confirm that I have provided the simplest configuration that can be used to reproduce the error I reported, instead of depending on remote servers, TUN, graphical interface clients, or other closed-source software.
• I confirm that I have provided the complete configuration files and logs, rather than just providing parts I think are useful out of confidence in my own intelligence.

No source files or tests are named. First reproduce the failure on Ubuntu with sing-box 1.13.20 or 1.13.21, TUN enabled, and a localhost domain, then compare against an older working version; done means localhost works again and the behavior is covered by a reproducible test or documented diagnostic.