Just replying to this with some updated information after my latest upgrade to Ubuntu 20.04 so I don’t forget on the next upgrade. I couldn’t get the fog installer to work without the -X option but figured out what the issue was. I needed to edit the /etc/pam.d/common-password file and change the following line to 10000 instead of 1000.
password [success=3 default=ignore] pam_krb5.so minimum_uid=1000
This was because the fogproject user was more than 1000, so changing it to 10000 let the installer work without needing the -X option and the password was updated properly. I then switched it back to 1000 so kerberos would work with my AD accounts.