Hi Staff, I came to post the same bug, but found this thread. Here is an image of why this issue might be happening. It seems like a scaling issue of the designer, take a look at how huge my cursor is compared to what Anna screen capped.
resolution is set to 1366 x 768 widescreen in windows 10.
Sorry for this crappy picture, if anyone knows how to screen shot in W10 and make it include the mouse cursor, let me know so I can post images without looking like an idiot lol.
You can see that the cursor when directly centered with the node, still hangs off either edge which might explain it activating a new node on click instead of opening the gradient editor.