Code block changing size on hover

After the latest version, My code blocks are changing size on mouse hover. Only seems to happen when there is a blank line in the code block. Using Chrome on Windows. Replicated with custom css disabled.

To reproduce, create a code block. Enter something like:

Test

Test

Remove focus from the code block, then mouse over. It looks like the ?crlf is being expanded. It shifts the whole page around and is visually distracting

This is a screen capture of the problem …

Has this started happening to anyone else?