Files being deleted from Temp directory before copy completes using Drag and Drop to another FTP app

When dragging large number of files from WinSCP to another application (such as Filezilla), the files in the temporary directory are deleted after approximately 120 seconds, regardless of whether the files have been copied to the new application (Filezilla in this case.)

I'm seeing this issue on version 5.17.1 running on Windows 10.

I am *not* seeing this issue on version 5.11.1 running on Windows 7.

I've been digging through the source code for a bit, but am not familiar enough with the project to be able to determine what might have changed. This could be Windows 10 related...I'm just not sure. I am not at liberty to upgrade the WinSCP version on Windows 7 at this time to test whether the problem would appear.

My temporary fix was to try and find a registry setting that allowed me to increase the "FDDDeleteDelay" default setting of 120, but it appears that's not possible as far as I can tell.

Is there any other way to modify or workaround that timeout (or alternatively, determine whether this is a bug or expected behavior?)

Where exactly are you dragging the files from? From the remote file panel of WinSCP? Where exactly are you dragging them to? Can you post a screenshot of your "Drag & Drop" preferences?
https://winscp.net/eng/docs/ui_pref_dragdrop

I can't remote login to the machine at this time for a screenshot, but I can say for sure it is set to "Download files via temporary folder".

The user drags files from the remote panel of WinSCP (connected to one ftp server) directly into the remote panel of Filezilla (connected to another ftp server), so that they can transfer files directly from one FTP server to another.

The file is indeed deleted too early. After approximately 10 seconds. I have fixed that:
https://winscp.net/tracker/1844

But it seems to be broken since 5.0.6 already. I'm definitely able to reproduce it on 5.11.1.

Can you send me an email, so I can send you back a development version of WinSCP for testing? Please include a link back to this topic in your email. Also note in this topic that you have sent the email. Thanks.

I've sent an email per your request. Apologies on the delay. I was on vacation last week and am just now catching back up.

I really appreciate your time here.

So I got confirmation today the "fixed" version definitely fixes the problem. Thank you so very much for that. When you have an opportunity, can you please let me know what official version this is fixed in, so I can inform the user?

(obviously no rush, since it's taken me this long to get back with you.)

Thanks again!

Thanks for your feedback.
This was fixed in 5.17.3, as you can see in the tracker:
https://winscp.net/tracker/1844