MacOS - Drag only works if both RMB and LMB are held down

I have a pretty robust open source software package I’m working on. It works great on Windows/Linux. It works pretty well on MacOS, except for the fact that dragging ONLY works if you hold down the Right mouse button and then the Left mouse button. Note that everything else works- clicking and right clicking both do what they should. Here’s the code if anyone wants to help. Help is greatly appreciated!!

Does the CustomDragAndDrop sample in the demo behave the same way for you? (It doesn’t for me.) If not then try to isolate what you are doing differently. If you’re still not able to figure it out then please provide a small runnable sample.