I see in the last update (Topaz AI 1.2.7.) that metadata should stay in the photo.
I have always had, and still have, metadata conflicts with photos edited using the Lightroom export to Topaz. And still the location information is thrown away.
I have the same issue with Photo AI 1.2.7
All works correctly with other Topaz products (Denoise, …): location info is preserved.
GPS location information is coming from my Nikon Z9.
That is probably why as LR may not send the data. You can test by doing an Edit in and create a TIFF, JPEG or PNG … don’t edit and save from Photo AI and see if the image has the data entered.
Then try the plug-in again, while it is executing make a copy of the image then see if the location data is there on the copy.