When I turn on syntax highlighting, the text becomes displaced, appearing one line below where is actually is.
- Ctrl+A displaying where text actually is (using DE screenshot tool)
- Ctrl+A displaying where text actually is (using Firefox screenshot tool)
I was able to produce this bug on FreeBSD using Firefox 67 and on Android 8.1 using Brave 1.0.99.
Addendum: This only appears to affect users using the Timeless skin.
Thus, to reproduce the bug,
- Switch to the "Timeless" skin in Special:Preferences.
- Enable "New wikitext mode" in Special:Preferences.
- Enable "Syntax highlighting" in the New WikiText Editor.