Hi.
First of all, Let me as a question.
Do your users automaticaly establish a connection/thread to the DB when they login? I have seen this type of problem before. This could be the reason that they are getting kicked out. I have definitely seen this!!
I would suggest shutting down the DB, then reboot with the DB down. Then bring the DB back up after the box is fully up and running. Now try a login as a user.
I would also check to see if you login script, /etc/profile, user's profile, and /etc/passwd files are not corrupted. Move in a new copy of your /etc/passwd if the first suggestion doesn't work at the top.
Here are some other suggestions that may be helpful.
This may be the problem.
https://www.unix.com/showthread.php?s...ry+permissions
May not be since they can login but it keeps repeating.
Here is another doc that shows how to lock out users. It may be helpful.
https://www.unix.com/showthread.php?s...ght=cant+login