Repro Steps:

1) Create a Page
2) Introduce any Element type onto the Stage (in my case, I got 100% repro with a ListBox Item, and a Button)
3) Create a Template from the introduced Element, and open it for Edit.
4) Within the template (Magenta border), select any Element within, then navigate to the Transform-->3D Transform section, and pick any 3D Property.
5) Input a new value into any of the 3D Transform Property fields
6) Attempt to MiddleMouseClick over the field into which the new value has been input, to clear the local value.

Observe how no result occurs

7) Click on the Property's 3-Dot menu, and select 'Clear local value'.

Observe how no result occurs.

Expected Results: All Properties can have their local values cleared.