Marketplace error when upgrading Concrete to newest version

I’ve just tried upgrading a local installation of Concrete V9.2.6 to the latest (9.3.2) and get a “Curl error 60” (full screenshot attached) when viewing the “update concrete” page in the Dashboard. Anyone else getting this as well?

The upgrade seemed to work after that.

Many sites I have updated have not been connected to the marketplace. As the issue appears to be related to the MP connection with the old marketplace, perhaps disconnecting from the marketplace would allow the update to complete.

This error occurred before running the update. The site had not been connected to the marketplace until that point.
After the upgrade completed, I tried connecting to the new marketplace for the first time and it worked.