How to reproduce: 1. enable editing mode. 2. open a document (e.g. odt) and make some editing (e.g. bold some text) 3. tap on the overflow button and then settings 4. press back on device to exit settings 5. your changes/edits are gone. Android version: 4.2.2 API 17
Confirmed with calc file edit Version: 5.5.0.0.alpha0+ Build ID: 076ed44
*** This bug has been marked as a duplicate of bug 106648 ***