Steps to reproduce:
- Log into http://en.m.wikipedia.beta.wmflabs.org/ and switch to Beta mode
- Go to http://en.m.wikipedia.beta.wmflabs.org/wiki/This_page_has_issues and click the edit button
- Make an edit and click continue
- From the preview screen, click on "This page has some issues"
- Click through the alerts
- Close the issues overlay by clicking the close button
Expected result: You're back at the preview screen with your previous edit intact
Actual result: You're back at the preview screen and your edit has been lost due to an API reload.
The problem does not appear to happen in stable.