I was able to test Photo Mechanic's FTP v6 Uploader template on Mojave and Sonoma, using the recent builds 6890 and 7086. I am able to see the folders listed on the Server. During my testing, I noticed the folders will not be listed if a folder name has been set in the Connections dialog Destination Folder on Server field. Is this field empty in your Connection Settings dialog?
We would like to try to recreate this problem on our test machines. Are using a public or private server? If you are using a private server, then would you be willing to try a special logging version of Photo Mechanic to help us determine the source of this problem? Any new Photo Mechanic builds will no longer run on Mojave. What OS are you running on the M1 Max?
Best regards,
--Bob