it seems you are 100% correct. #_users seems not to be shared, although the #__kunena_users is shared.

in the template/sharing we have selected to share joomla users as well as the kuena forum, but something is clearly not working i guess.

not sure where we are going wrong...

If you have physical users, this mean that you originally created the slave site with independent users.
This is a decision the first time you created the slave site and can not be modified later.
So if you try to change the JMS Template rule to enable the sharing after you created the slave site, this will not have any effect on the Joomla users that are created the first time you defined the slave.

The only way to get users share is to delete completely the slave site and clean all the DB table and rebuild the slave from scratch.
You can not convert existing independent users into shared users as the ID can be totally different.

I am aware that it has to be done initially... i deleted and re-installed the slave site, jsut to be sure. The template has been set to "share" users from the beginning.... so something is not working properly.

No. It is not possible to JMS Multisites do change a shared table into a physical table.
So I can guarantee you that when you created the slave site, you decided to have a physical user table and not have decided to shared the users.

ok...so how do i choose to share the users exactly? in my template the share user box is checked... but it is not working that way.

maybe this helps..

The sharing of the user can only be decided when you created the slave site and not after.
Once a website is created, it is no more possible to convert a "standalone" users into shared users.

If you just have 1 or 2 users like the super admin (62) and perhaps a second user id 63, you could perhaps try delete manually the users and rebuild the slave to create the sharing but when you already have plenty of users, this is not possible.
You need to be sure that ALL the user ID present in both website are absolutely identical.
When you have 2 different website that had created users (with their own users ID), then you can not have a same user ID (X) that correspond to the same users in the other website.

Sharing the users is described in tutorial video 16 and must be decided when you create the slave site - not later.