Groups not showing posts by users other than admins

[DanAdair]

Hi again. I've created groups, and have chosen which categories should 'feed into' each group.

If I post in one of the associated categories (I'm an admin) the post will appear in the group.
But if a non-admin posts, it doesnt seem to pull through to the group.

Is there a setting in Groups that I'm missing?

Many thanks

[baris]

When a regular user posts is their post id added to this sorted set in the database? group:${groupName}:member:pids