Spark online users issue


Good day.

Some of the spark user outside the network when they login, they only see 1 or 2 user online but it has 10 users online. there is no error log. i restart the openfire server and try to login again and now they can see all the online users.

what causes of this issue? is there any setup i need to adjust so that it wont happen again? how to adjust cache and best/recommended value for each cache?

Thank you.