Still not solved.
The problem is - I've got legacy users which have been deleted from the mango server when people left the company.
I'm unable to add them back (error says username already exist) and I can't see them in JSON export for Users.

this issue is still valid in Mango version 3.7,
have to use old UI to add emails.

Thanks Matt.
This didn't work for me. I've set the value to 5 minutes and after 15+ minutes everyone was still showing as Active in Events and I was able to navigate around without logging in again.

Hello,
We've got a situation when people are logging into the Mango and leaving their sessions running for a while, which is increasing internet traffic.
Is there a way to gracefully log out someone without restarting the Mango please?
Appreciate your help.
Elena