405 The resource you tried to create already exists

Nextcloud version 12.0.0
Operating system and version Windows 10
Apache version 2.4.25
PHP version 5.6.3
Is this the first time you’ve seen this error?:I think so

Can you reliably replicate it? (If so, please outline steps): Start NextCloud sync client on Windows 10

The issue you are facing:

I am syncing from removable USB thumb drive. It has a persistent drive letter assigned (E:) - if the sync app sees it is gone, does it then try to remove all the files from NextCloud? Because when I reconnect the drive the sync app is trying to copy everything back to the cloud, all of which are resulting in errors (subject line).

How do I prevent this? Shouldn’t it just check and see that they are the same files, and then never try to copy them up to the server