Sorry for late answer. Actually I was interested in the panel status bar. Unfortunately you have it hidden for the remote panel. Can you display it and post a new screenshot?

the requested attachments are included

Thanks for your report.

Please attach:

- screenshot of the main window just before you press the "custom command" button
- screenshot of "Storage" page in Preferences: https://winscp.net/eng/docs/ui_pref_storage
- session log file (note an exact time you click the button).

This morning, I have already called Beyond Compare for three separate files and the behavior is consistent. When I call it for the fourth time, I get 4 results back one at a time:
remote file1 compared to local file4
remote file2 compared to local file4
remote file3 compared to local file4
remote file4 compared to local file4

All of these files are in the same remote and same local folder. I suspect this has something to do with the temporary files and temporary folder being used when downloading the remote file for comparison on the Windows side.

I have a button configured to call Beyond Compare with this syntax:
"C:\Program Files (x86)\Beyond Compare 3\BCompare.exe" "!" "!^!"

Only two files are selected, but on some occasions, Beyond Compare is called multiple times. The last call is the one I want. The 'early' calls seem to be for files that were selected for previous calls.

Is this some sort of cache problem? Windows 10 running on HP elitebook 840. The remote machines are RedHat Linux 64.