In RTL, blocks don't return to their position after dragging outside the area

[noamraph]

Expected Behavior

When blocks are dragged outside the area, they should reappear in their original position.

Actual Behavior

In LTR this works as expected. In RTL, the blocks appear in another position.

Steps to Reproduce

Open vertical_playground.html. Change direction to RTL. Add a block to the area. Drag it outside the area, to the pane on the left. It appears in another position.

(I noticed this in scratch, when copying a block into another sprite by dragging it. The block is moved to another position.)

Operating System and Browser

Ubuntu 16.04, Chrome Version 84.0.4147.89 (Official Build) (64-bit).