Ticket State after Customer adds note

[Paulc]

Hi. We would like to configure our system to amend the ticket state after a customer has added a note to a ticket so that it can easily be spotted.

This is working fine when a customer submits an update via e-mail, but when they add a note via the customer interface, the state remains unchanged (we have not given customers access to amend states manually).

The config we have at present for Ticket -> Frontend::Customer::Ticket::ViewZoom is:
###ArticleType webrequest
###SenderType customer
###HistoryType FollowUp
###State No
###StateDefault Customer Responded (this is a valid state added via AdminState)

Can anyone help so that when a customer adds a note to a ticket via the customer interface it also updates the state?

Thank you.