Sourcetree becomes the active app when dragging anything over a covered window

when I drag and drop anything on my Mac, sourctree decides to become the active app, and brings it window forward, and usually covers the app I'm trying to drop into.

This happens if the cursor moves over any portion that's not obscured.  I don't see the reason for this, and it makes drag and drop very difficult.

Then I have to stop my drag and drop, move the source tree window out the way, and then do the entire thing again. 

It's pretty disruptive to my workflow, and I'm hoping there could be a way to disable that behavior.

It's also not needed because we can now rely on the built in spring-loading option under the Pointer Control settings that accomplishes the same task, but with a predictable hysteresis. 

Thanks!