Lost selection during copying

[zer0]

Something mysterious is causing loss of selection in an inactive tab. Basically, I do this:

1) Go to a tab, select some folders, click on another tab in the same pane and copy them over using TeraCopy.
2) At some point during this process, the original tab (source) loses selection of those folders for an unexplained reason, because I do not even visit that tab until the time I go back to it to check this erroneous behaviour occurs.

I initially noticed it after copies completed but now check during the copy process and it happens then too. I realise that's not a lot go do on, but not sure what further troubleshooting I can do. Bizarre!

[highend]

Copy handler inside XY is...? Not TeraCopy?

[zer0]

Copy handler inside XY is...? Not TeraCopy?

Not sure if I understand the question...here's the visual confirmation:

[highend]

And the same issue occurs when XY's internal copy handler is used?

[zer0]

And the same issue occurs when XY's internal copy handler is used?

Haven't tried it -- not a fan of how XYcopy handles copies to USB drives -- but struggling to see how choice of a copy handler could affect the selection, especially since TC just accepts a list of files XY wants it to copy.