Currently, whenever a customer replies via email and a support agent replies to that type of reply, that type of support agent reply shows in the Customer Portal Timeline, which of course makes sense.
However, when a customer replies through the Portal Ticket itself, and the support agent replies to that type of reply, it creates a new thread and thus subsequent replies from either side (I believe at least the support agent) do not show in the Portal Timeline, which of course does not make sense and is not intuitive at all (there’s not even a cautionary message/tooltip when a support agent is about to reply to a Customer Portal reply).
It’s even weird in its own Hubspot logic, as when the customer decides to reply via the Portal, it shows (even though technically it creates a new thread and therefore should not show by Hubspot’s supposed logic), but only replies to that reply do not show.
In a nutshell, the intuitive approach should be adopted, in that whatever reply a support agent replies to should be included in the Portal Timeline.
I don’t know why the Portal Timeline show logic is in its current state today but from our side, it just does not make sense.
If needed, here is reference to the HS Support Ticket that led to me create this Idea if clarity is needed: 27669926763