Lost connection - by: bosimo

Hello,
I'm using projeqtor 5.2.5 hosted on a linux server running PHP 5.5

Since the installation few days ago, it was working fine but since this morning I got disconnected, due to lost connection, and I wasn't able to connect again as the login screen accept the password but bring me back to login page instead of home page.
I had to activated the option "remember me" to keep connected, but I'm frustrated by frequent disconnection, for example I'm not able to link an activity with a document as the field is replaced by disconnection error message.

I found a similar problem described on your forum with older version of projeqtor, but instead of this user, the opcache is desactivated on my side under PHP, so it's not the origin of the problem.
I also already faced this problem in the past when I tested some new version since 5.X

Any idea on how to resolve this issue please, let me know if you need anymore information.
Note that I didn't change anything on the server or the configuration file before the problem happens.

Thanks for your help.
Regards