Found this on the Zenfolio site...
Partial Outage Zenfolio Classic - Upload
Update
As we are working to resolve, we identified an issue where some users may experience upload failures/duplicate errors. Thank you for your patience while we work on a fix.
Posted 3 hours ago. Feb 04, 2024 - 09:13 PST
They seem to be on to it now, though this did start a few days ago - Time will tell