Steps to reproduce:
1) Open a tab with an editable tree.
2) Make the first row active.
3) Start to edit the field with Selection widget in the first row.
4) Press the Down Arrow key N times
(N is the number of choices in Selection widget).
5) The first row becomes active instead of the N+1 row.
+ win32 title: Bug in editable trees with Selection widget (Desktop Client for Windows) -> Bug in editable trees with Selection widget