Edit page instructions do not hide in Edge after adding first block

The instructional message on the editor does not disappear in MS Edge after adding a block to the story. This is likely a lack of support for or problem with the specific CSS and JS used to hide the instructions and show the editing area with the new block.

To reproduce: Add a new block

Expected: The instructions disappear and the new block is visible

Actual: The new block in the editing area is shown, but the instructions are not hidden and show up beneath the editing area