Sometimes I’m having an issue with 3.1.0 on Unity 2019.4.8f1 where Drop Variable gets stuck on the cursor after dragging a blackboard variable onto the graph, and clicking to Set or Get a variable doesn’t clear it. It seems to be caused by a minimised Blackboard Variables box in the graph, and it clears if I maximise the Blackboard Variables box.
Thank you for the bug report! I was able to reproduce it.
Just to clarify, the reproduction is that you have the Blackboard inspector in the Graph Editor minimized and you are dragging a variable from the Blackboard inspector on the gameobject itself (rather than the Blackboard on the Graph Editor)?