When changing the position of an window, the current code provides for changing X or Y individually, and this appears to work with most window managers.

Except for the one on OEL 7. with that wmgr, both X & Y need to be set, otherwise the window uses the same value for changing both X & Y

A compatible change can be made to set both X & Y if either is changed.

Found with hello.HelloWindowManager, the up,down,left,right buttons.

This affects FX 8 as well