Placing Prefabs with Drag & Drop will move around the same one instead of instancing a new one

I made a video that shows the bug:

While I really appreciate that drag & drop has vastly improved in the latest versions, this one still prevents me from casually dragging prefabs into the scene.

I have the same bug.

Moving the “Project tab” to the upper left position of the layout resolves the issue…

I also have this issue. Moving the project tab to the upper left also fixes it for me. Strange.

Behavior is unchanged in 5.6.1f1