Combo box does not always open on first try

Steps to reproduce:

• Make sure Properties view is open but not focused
• Drag and drop Image from Components to 2D View
• Open Properties view
• Click arrow in Image - Source combo box
• -> menu briefly opens and then closes. Would expect it to stay open.
• Second time trying, menu stays open
• Reproduces also e.g. in Effect Composer view with effect texture combo box.
• Please see attached recording