Nextcloud icon on a folder, but no sync connection?

Nextcloud version: 22.0.0
Desktop operating system and version: Windows 10

The issue you are facing:
I see a Nextcloud icon on a Windows Explorer folder on my desktop computer. I do not see that folder either in my online Nextcloud instance or my Nextcloud desktop client.

Can I be sure that this is not a Nextcloud synced folder if it does not appear in my Nextcloud desktop client?

If it is not synced should I just change the icon via the properties dialogue for that folder?