after login vbulletin give me some other user account (have video)

[pjk]

My login is "pthunya" but in video you can see that vbulletin gave me "Kongkasit" account (he is my user, I don't know him personally, I don't have his account password and never login his account on my computer before).

but after I left forum home to forum section, vbulletin gave me correct login name as you see in video.

[In Omnibus]

YouTube has nothing whatsoever to do with vBulletin. It's possible your account was hacked. Try using the tools.php file to reset your password.

What you can do is create a new administrator by following these steps:
1) Register a new user. Keep your password safe.
2) Upload the tools.php file found in your do_not_upload folder to your /core/admincp directory.
3) Upload the /core/install/ folder from your upload directory.
4) Visit your site at /admincp/tools.php
5) Enter your Customer Number.
6) Choose the tool to turn a user into an Administrator.
7) Make the user you created in step 1 into an Administrator.
8) Delete the /core/install folder from your server.
9) Delete the /core/admincp/tools.php file from your server.

[Wayne Luke]

Turn off Varnish. Turn off whatever proxy-enabled CDN that you're using.

[pjk]

Sorry that the name of video clip make you confused, It's my own recorded clip of the problem I found, I login my account "pthunya" but if I login it's at forum home, vbulletin just gave me another user account instead of mine until I goto another forum section.

YouTube has nothing whatsoever to do with vBulletin. It's possible your account was hacked. Try using the tools.php file to reset your password.

What you can do is create a new administrator by following these steps:
1) Register a new user. Keep your password safe.
2) Upload the tools.php file found in your do_not_upload folder to your /core/admincp directory.
3) Upload the /core/install/ folder from your upload directory.
4) Visit your site at /admincp/tools.php
5) Enter your Customer Number.
6) Choose the tool to turn a user into an Administrator.
7) Make the user you created in step 1 into an Administrator.
8) Delete the /core/install folder from your server.
9) Delete the /core/admincp/tools.php file from your server.

[pjk]

It's just new site. doesn't apply any cache like Varnish or CDN or even memcache yet.

Turn off Varnish. Turn off whatever proxy-enabled CDN that you're using.

[pjk]

Most of time I have to login many times as you see in this clip, and sometime after I finish login it gave me another account like above video.

[Wayne Luke]

The symptoms you describe are caused by server level caching. We have no control over server level caching and cannot resolve issues with it. You need to verify with the Server Administrator that things like Cloudflare or Varnish are not implemented on the server or the server's network in regards to your website.

[pjk]

I'll contact admin of my server, Thank you.