Hi Chris,
I'm able to connect and upload to our Zenfolio test account in Photo Mechanic Plus build 6097 without issue.
I'd like to see your Photo Mechanic log file. You can get access to the PM.log file from within Photo Mechanic's Help menu and choose "Reveal Support Data...". When you're composing your reply use the 'Attachments and other options' link and select the PM_log.zip file to upload.
Thanks,
Jerry