My Cloud EE2 Ultra keeps trying to sync deleted file

My set up is that I have a Win 10 desktop and a win 10 laptop both syncing to my EX2 Ultra, in this case to a folder named Downloads, using WDSync.

I downloaded a file, R-4.0.1.tar, to try using the R statistical software package. After fiddling with the programme I decided to uninstall it and remove the original downloaded files. This I did from my desktop, assuming the sync process would remove it from the NAS and the laptop, as that it what normally happens. Howver, somehow it kept being restored to the PCs and the NAS. So, I disconnected both the desktop and the laptop from WDSync, deleted the files from all three machines (including the recyle bins) reconnected WDSync, and now WDSync is busy trying to resync the file on my desktop (which it says it is unable to) and the NAS drive is spinning quite loudly.

Any ideas what might be going on?

This continues and is very ood. Despite numberouds attmepts to delete the files, rebooting the NAS, WDSync is still trying to sync this - and is just trying, unsuccessfully time and time again. Here’s a picture for some clarity.

What I don’t get is why it says that the file is locked or in use. As far as I can tell it is neither.