Hello Sonya1,
Thank you for your instructions.
I am surprised that you are not able to replicate the problem. Are you sure you are not installing the
fax driver as an Airprint fax device? Because that will _always_ work. This problem only show up if registering as a LPD device.
It is worth mentioning that my version of Safari is 11.1.2.
I have followed the Uninstall, Reinstall procedure more that 15 times on my Mac here while diagnosing the problem to no avail. I have since installed the fax driver on 2 more newly installed High Sierra Mac resulting in the same problem and same console messages.
Please check whether your High Sierra Mac is running Safari 11.1.2, and whether you accidentally registered the fax using Airprint.