SW Pro 2017 SP1
With the Measure Tool dialogue box open I get strange actions when right button clicking on parts/assemblies in the feature tree (LHS strip window).
Measure dialogue box open and measure tool active..
Measure dialogue box open and select tool active.
Measure Dialogue Box closed
The symptoms are very similar in part editing too. Took me a while to work out that the measure dialogue box was the culprit.
Don't remember this being the case in 2016 and earlier