I typically use the keyboard for navigation when at all possible and I have noticed some odd behavior in the Blueprint editor when scrolling through a list of Variables in the My Blueprint pane.
When I select a variable with a the mouse, the details pane is populated with the variable and default value sections as expected. However when I then scroll to other variables using my keyboard I find that the Details pane only updates the Variable details section. The Default Value section remains focused upon the original variable selected with my mouse. Selecting any variable using the mouse only updates both sections in the expected fashion.
This image shows what I see when using the keyboard:
This behavior was observed in version 4.4.1