Intermittent Sycnhronize Trouble

I'm having a problem with the synchronize command over FTP that I don't recall having before. I have two servers running fully updated Windows 2016 that have the same setup -- synchronized clocks (one actually synced with the other), and both are set to use daylight saving time, the same timezone, locale, language, charset, etc. For some reason the synchronize command arbitrarily skips many random files and re-downloads other files that don't need to be transferred, since they have not changed and their timestamps are the same on both sides. However, if I open WinSCP's GUI (Commander interface) and manually select the folders, and drag and drop them, telling WinSCP to only copy the newer files, it will correctly transfer all of the new files, skipping those that have not changed. The timestamps also appear correctly in WinSCP's GUI, so if there's a misinterpretation of the timestamps, it appears to be internal to the synchronize command. The client is WinSCP 5.9.5 and the FTP server is FileZilla Server 0.9.60.2 beta -- the newest and recommended download from their site. This problem is also occuring for another client system that is running fully updated Windows 10 and WinSCP 5.9.5. Have you encountered any new issues of this kind so far?

I'm using the following in my scripts on the client side:

option batch continue
open ...
lcd ...
cd ...
synchronize local -mirror -criteria=either -delete -preservetime -transfer=binary -filemask=*|*.log

(Note: I have added "-preservetime" to try to deal with this issue, but it hasn't helped.)

I'm running the script with:

"C:\Program Files (x86)\WinSCP\WinSCP.com" /script="C:\Path to script\DownloadScript.txt"

Thanks,

Tim

Please attach a full session log file showing the problem (using the latest version of WinSCP). Name one of the files that was transferred and should not have been (and vice versa).