Thanks for filing this. 

Tried signing up to https://beta.ability.es/#/base/login as per video, to test this but I am not seeing any option to proceed with signing in there.

teo.eterovic@: If possible, could you please attach any test file with the above test case to try a repro from our end and check where this regressed.

Removing Blink>DOM>Event since the issue sounds specific to Drop event.

Huh. I can't get any drop events to happen.

https://plnkr.co/edit/PO7Nt1TshKcBCduDiiOV?p=preview

do you mean dropend? or drop?

+dcheng, who knows about drag drop

According to the spec [1] drop is supposed to fire on the event that receives the drop. If the drop occurs outside the browser, there's no target, so there's no drop event. AFAIK, we do fire dragend on the source, and that's the right way to update the UI to reflect transitioning from drag-and-drop mode back into the normal interaction mode.

OP: If you can help me with additional information, such as code, I'd be happy to take another look at this issue. The video is not enough for me to figure out what's happening.

#6: You're not seeing a drop because the plnkr.co doesn't have the correct drag-and-drop setup. Unfortunately, this API is unnecessarily complicated. AFAIK, in order to get a drop, you need dragenter and dragover event listeners that call event.preventDefault(). Missing the event.preventDefault() call in any of these listeners is taken as a signal that the target element doesn't accept the drop, so there's no drop event.

[1] https://html.spec.whatwg.org/multipage/interaction.html#dndevents