Marcel Taeumel uploaded a new version of Morphic to project The Trunk:
http://source.squeak.org/trunk/Morphic-mt.1642.mcz

==================== Summary ====================

Name: Morphic-mt.1642
Author: mt
Time: 3 April 2020, 5:52:32.157206 pm
UUID: 774f60b6-f208-a246-bbd8-f07c0d5d0fb4
Ancestors: Morphic-spfa.1641

Adds a missing reset of the potential drop row to avoid visual glitches. As you can see, the hover row and the potential-drop row are both related.

=============== Diff against Morphic-spfa.1641 ===============

Item was changed:
  ----- Method: PluggableListMorph>>mouseLeave: (in category 'event handling') -----
  mouseLeave: event 
  
  	super mouseLeave: event.
  	self hoverRow: nil.
+ 	self resetPotentialDropRow.
  
  	Preferences mouseOverForKeyboardFocus
  		ifTrue: [event hand releaseKeyboardFocus: self].!