Thanks for the problem report, which we have been able to reproduce. It is definitely a bug and it will be fixed in the next update.
In the mean time, if you are familiar with using the Windows REGEDIT program to edit the Windows Registry, you should delete the following key:
You will find that dragging the pane all the way to the left sets a value of 0x0000000 (0) and for some reason, once at 0, it can’t be dragged again.
Of course be sure not to delete any other key except this one. Reinstalling Formativ may achieve the same result.