openssh-server prompt halts cloud-init

Hello, I've been using this debian image for a couple months without issue: ami-071175b60c818694f. Today when I run my CFN template to start my cluster, stack creation completes normally and Im able to ssh into my public instance. But I find none of my user-data script has executed. catting /var/log/cloud-init-output.log shows a prompt from openssh-server: -------------------------- Configuring openssh-server: │ A new version (/tmp/tmp.99nOdMR8Nk) of configuration file │ │ /etc/ssh/sshd_config is available, but the version installed currently │ │ has been locally modified. | What do you want to do about modified configuration file sshd_config?

I did not change any ssh config: $ ls -lrt /etc/ssh/sshd_config -rw-r--r-- 1 root root 3245 Jul 11 04:26 /etc/ssh/sshd_config

Another article suggested rebooting, but that does not run my user-data script. Is there a way to tell openssh-server to stop blocking cloud-init?