Hi!
I’m not sure if this is a bug, but it seems strange to me. If you share a ticket with a requester it seems like they are granted the ability to mark that ticket as closed in the portal.

From the perspective of the requester to whom the ticket was shared:

Then, when you reply from here you can not delete the message in freshservice even as an admin:

Any idea what is going on here? I cannot seem to find an option to remove the “Mark ticket as closed” for requesters for shared tickets.