Hello Jason,
Thank you for the inquiry. Can you please confirm the options that you are observing. I have confirmed that the 'Auto responder' option for 'Limit responses to once daily' is available in 12.3x, 12.4.5364, and 13.x under the My Settings tab.
There could be a setting that is enabled under the Technical tab for the Domain. Please see if there is a checkmark for 'Restrict auto-responders to once per day per sender'. If so, the option would not be present.
Please let me know if you need assistance and open a Support Ticket.
Thanks.