thanks for helping me out.
Where can I find dmarc/spf in roundcube?
dig +short -t txt example.net dig +short -t txt _dmarc.example.net
What I mean is that if everything was working. Probably some external factor is causing your replies to not be delivered. If spf or dmarc is enabled it could be an issue. Gmail is also blocking your auto replies when dmarc is not there. I had a similar experience recently.