See screenshot.
"You have now rights to answer to this post"

hi

So members of a specific blog cannot comment on that blog?

EDIT As usual too quick to reply and working from a 8" tablet ~ not ideal and i tend to write up as i work on problem, not text just a solution :(

"Registered Community Users who are not Members of a certain collection can not comment, although anonymous user can. This way, registered users have less rights than not registered ones."

Collection: collection >Settings>Group perms ~ sets the permissions for each group ID by level and I have anonymous users with no option to comment

when people register they are set at a level Users > Settings > Registration and Login

I think i'm making a mess of this resonse and repeatedly editing must be annoying for readefs so i'm logging off for now. Sorry for the messy response

yep, you need to properly set the permissions for the group, probably the "Normal Users" group.

@fplanque I tried to set permissions and took a long time for playing around with different settings - but nevertheless: whenever I set permission to a registered User or Group to comment the user or group automatically got member status.

So please check and perhaps - regardless of my own unsuccessful attempts - you know the path for setting community permissions i a way, community users are allowed to comment without becoming members.

Why do you need them to not be members?

@fplanque community users are allowed to see posts of different collections with permissions set to community. Members of a collection are allowed to see more special, more valuable posts.
In other words: community posts are for leads, member posts are for customers.

But no lead would understand, that more rights on one hand (see community posts) cause less rights (no commenting) on the other hand.