Maybe a reason why your self-hosted sync is deadly slow

Have you read a contributing guide?

• I have read CONTRIBUTING.md
• I have searched the existing issues and didn't find any that were similar
• I have considered creating a pull request with fixes instead of a bug report and want to proceed

Current Behavior

So in README.md, the tutorial gives me an example:

echo 'EXTERNAL_LISTEN_HOSTS="<yourExternalIp1> <yourExternalIp2>"' >> .env.override

I just followed it.
But I found the self-hosted sync is deadly slow.

So I check by cat .env, and found there is another parameter : EXTERNAL_LISTEN_HOST, and its default value is '127.0.0.1'.

So after I rebind it to my public IP, everything is solved. It syncs succeedly in several seconds.

Maybe it's the key of problem, or am I suck?

Expected Behavior

Maybe change the example into :

echo 'EXTERNAL_LISTEN_HOSTS="<yourExternalIp1> <yourExternalIp2>"' >> .env.override
echo 'EXTERNAL_LISTEN_HOST="<yourExternalIp>"' >> .env.override

Steps To Reproduce

1. Follow this repo's readme.
2. Rent a VPS on Singapore to self-host this docker container
3. Move into China mainland or any other places with restrict national firewall.
4. Then you may find it's very, very, very slow to sync, even with proper VPN Setup.

Environment

- OS: Win11 2024H2
- Version:2024H2

Anything else?

Thank you for review.

Start by comparing the self-hosting tutorial in README.md with the .env defaults, focusing on EXTERNAL_LISTEN_HOSTS and EXTERNAL_LISTEN_HOST. Reproduce the Docker Compose setup if possible and verify whether adding the second setting resolves the reported sync delay. Done means the README example accurately documents the required configuration.