Notifications Scheme so that current assignee is notified only if they belong to specific group.

[Antonios Chaidaris]

As the name suggests we have two groups in our Service Management Project.

For the one group, If a member becomes the current assignee of an Issue in the project they should get all notifications, in platform bell notifications as well as emails.

For the other group, a member shouldn't get any notifications, in platform bell notifications as well as emails, even if they become the current assignee.

As it stands it is not clear how this is possible through the options given through the Notification Scheme.

1. We've tried to implement this through the notification scheme which did not work since it is not possible to combine conditions i.e. if current assignee AND in group_x.
2. We've also tried to use automation and combine it with a custom notification scheme.
   1.  Set all notification of the scheme to go only to watchers.
   2.  Create automation to set the current assignee as watcher only if they belong to group_x. 

The automation of 2.2 actually worked but the notification behaviour was inconsistent to watchers.

1. People that had turned off the setting to get notifications as a watcher were actually receiving some notifications.
2. People that had turned on the setting to get notifications as a watcher were not receiving notifications.

Any thoughts or advice on all this?
Has anyone ever had a similar issue and how did you approach it?