When I log in I have to refresh the page

[Divvy]

Hello guys,

Can someone give me a little help here please?

Im facing some problems with my vbulletin.

First I thought that it won't let me log in. I try to log in with my admin username and password, but it returns the non-logged-in homepage again. But I did a refresh and I was logged after all.

Than, when I read new posts doesn't mark as read, I always need to refresh page to update posts status.

What could be?

I tried this but didnt worked for me:
https://vborg.vbsupport.ru/showpost.php?p=2079105&postcount=2

Hope someone can help me :)

Thanks!

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I tried this and now is working fine:
AdminCP > Settings > Options > Cookies and HTTP Header Options
Add No-Cache HTTP Headers > Set to "Yes" and save.

But this may cause server load to increase due to an increase in page requests.

Isnt there any other solution for me?
How to fix this issue without the option above?

Thanks!

EDIT:
Btw, this is my .htaccess file: http://paste2.org/AFz7aDac

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Ok, it seems that Cookies and HTTP Header Options worked for me...
But my users login time is too short, they always logoff from morum after a few time of using.
How can I fix this?

Thanks!