Hi Ken.
Topaz Gigapixel 1.0.7 is working as expected with the Standalone version and as a Plugin for myself.
I don’t work for Topaz but, I am curious to know are you using the Standalone version or as a plugin within Lightroom, Photoshop or similar software
Standalone version:
If you were using the Standalone version on saving the image Gigapixel adds information to the image file for example; you may have a Prefix added then > Image File Name then > a Suffix added then > very compressed-2x-faceai v2
Are you seeing that extra information on the saved files within the original folder and if you added a Prefix then the file will save in a different position within the Folder File list.
In addition, have you checked you’re not saving to a different location Folder.
Plugin:
If it’s a Plugin then can you provide more information on the steps you are taking before, during and after this behaviour.
In the meantime, have you tried running the Installation again in case you have missing models for instance.
Here’s some information from Topaz about Models
And Troubleshooting
Here’s the link for Gigapixel 1.0.7 for both Windows and Mac
Windows
https://downloads.topazlabs.com/deploy/TopazGigapixel/1.0.7/TopazGigapixel-1.0.7.msi
Mac
https://downloads.topazlabs.com/deploy/TopazGigapixel/1.0.7/TopazGigapixel-1.0.7.pkg
And the link for all previous versions of you wish to Rollback and if you do decide to Rollback there’s no need to Uninstall, Remove or Delete your current version this will be done during the Installation Process.
Here’s the link to contact Topaz Support if these don’t resolve the issue
Topaz Support
Hope this helps and have a happy New Year 
