Nginx is unable to reach st2auth. Make sure service is running

[DesireWithin]

Hello,
I've had this problem for some time.
At the beginning, the first login request always failed because this reason. But the second login request will success after waiting for 30 seconds or more.
But now, I can't login st2web anymore.

Nginx serivce is running well, as well as st2auth.
I open LDAP feature, stackstorm version is 3.4 on oracle linux 8.3.

I try to watch logs, the phenomenon is as follows:

• 0 seconds I input correct username and password, click CONNECT
• +0 seconds /var/log/st2/st2auth.log shows `INFO logging
• +30 seconds /var/log/st2/st2auth.log shows [CRITICAL] WORKER TIMEOUT and Worker exiting . And at the same time, /var/log/nginx/st2webui.access.log shows I POST my auth tokens from Mozilla Firefox

Is it a LDAP issue?

[DesireWithin]

It's maybe a LDAP issue.
I consult my windows colleague, I change another LDAP server and run st2ctl restart-component st2auth
It looks OK now.