Steps to reproduce:
- Go to Special:CX
- Make sure you have enough drafts or published articles so that you can scroll down
- Click the green "Start a new translation"
- Click the source article name field
- Type es (actual text does not seem to matter)
- Click source language selector
- Type es and press enter (actual language does not seem to matter)
- Click target language selector, screen will scroll up (if doesn't happen, try to repeat from last step)
Google Chrome here.
PS: Not attaching screenshot because Phabricator does not let me: