Confirmed Editor - Insert Code takes the first line only

[smozgur]

Affected version

2.3

If you select a multiline code and use the code button on the editor, only the first line of the selection is copied into the Insert Code popup window. I believe this was fixed in 2.1 or 2.2, but it looks like it is back.
I hoped it was in Safari on Mac only, but also the same behavior in Chrome on Windows.