A while back, we added a UX enhancement that disabled sending the OOO
message when an agent had replied to the conversation in the last 5
minutes.
https://github.com/chatwoot/chatwoot/pull/11073
This would not send a "we will be back" message even if that reply was a
private note. This would break for bots that posted private notes, and
even for agents who need to just add a note and not actually reply to
the email.