Incorrect behavior of a cross-staff measure rest
In the attached score, select the measure rest in measure 1, bottom staff and move it to the top staff (ctrl + shift + ↑)
Select the rest, open the inspector and adjust either the x or the y position of the rest by clicking the arrows. After clicking twice, the rest disappears and will reappear only after a relayout of the score occurs.
This issue also occurs when autoplacement is turned off for the rest.