Several reasons why this can happen. The forum's server might be doing it for load balancing reasons, or, it could your computer or its Anti-virus software cleaning up cookies.
Just spotted another: looking at who has been active in the last 20 minutes on the bottom of the FORUMS page, I saw the list includes MyCreditDom çàéì äî çàðïëàòû 2
This is garbage. It suggests either a legitimate login has been corrupted, or some sort of hacking attack is underway. Corruption is more likely, either message mangled in transit over the internet, or inside a users cookie, or in the servers cache.
I don't know how this forum's software deals with mangled logins, but one method is to reject further attempts (basically invalidating the users cookie), and to purge the server cache, Depending on how bad the server thinks the problem is, it could clear the cache completely and force everyone to login again fresh and clean, or it might delete groups of logins it's unsure of. Group cleansing might explain why some people are more inconvenienced by dropped logins than others.
What happens depends on how the server is programmed to manage logins. There's always a handshake, and they can get in a muddle. What the forum does isn't straightforward, for example, if a user has several computers, he can only be logged on from one of them: any other is logged out by the forum
For what it's worth, I was trained to never leave a computer system or application logged on. Although convenient to the user, it wastes computer resources, increases the chance of the login going wrong, and introduces a bunch of security problems. No security issue staying logged in to this forum except it creates a bad habit. Not clever to wander off without disconnecting from an online banking session, or anything else involving money or privacy! I always log out of all websites at the end of every session because laziness is far more likely to cause a computer security crisis than a careful routine.
Dave
Edited By SillyOldDuffer on 10/01/2022 16:01:50