Syncing a New Folder Created with the Desktop Client on Mac

I am running a current version of OwnCloud on my CentOS 6 server. I use two Macintoshes (OSX Sierra 10.12.4) with the latest OwnCloud Desktop Client. On my Macs, the local folder is ~/ownCloud.

On one Macintosh, I created a new folder inside the ~/ownCloud folder by duplicating another. The plan is to allow it to synchronise and eventually to make it available to the other Mac.

The Desktop client does not show the new folder at all, and doesn’t seem to be interested in synchronising it. On the Finder, the other folders have the :white_check_mark: icon, but not the new folder. That obviously means something, but I don’t know what.

What extra step do I need to take to synchronise this new folder?

Which client does not show the new folder? The "other" desktop client?

What do you see in the "Sync Protocol" tab in "Activity" in both clients?

How does it look on the ownCloud webinterface?

The original client doesn’t show the folder. It’s there in the Finder, but the client doesn’t show it.

The Sync Protocol tab shows nothing at all — it’s empty.

The web interface doesn’t show it either, but that’s not surprising, as I don’t think it’s been pushed that far.