panes cannot be resized on external display

[Wiljo]

When moving the app window to an external display, the panes for logging, local/remote structure and such aren't available and thus it is impossible to resize any.
When moving the app back to my primary display, they are available and I can resize. Upon moving to external again, they become unavailable.
Sometimes, after a while and probably something I do, the whole thing is functional on an external display as well but I cannot say what the action is.

There seems to be a vertical handle in the bottom status bar in this case, about half way the left pane.

This appeared in one of the two last updates.

[Wiljo]

screenshot