I finally got a screencast recorded of this behavior.
What I find is often I cannot drag a block underneath another container or block, especially if I’m going from one container or grid to another, or they are nested and predominantly when there is no block below where I’m dragging already (bottom of grid, bottom of container, bottom of column.
The only thing that seems to fix it is if I drag above the nearest block. Then drag it down to where I want it.
Have you noticed this behavior before? Seems to be the same for me in Chrome and Firefox, Win10.
Thanks for any insight you can provide, I appreciate this may not be a GP specific thing and more of a WP core issue.