Found on enwiki (wmf.11)
- On Preferences-Recent changes make sure that the option "Show only likely problem edits ..." is checked.
- Go to Contributions page and un-check the page option - "Hide probably good edits".
- Click on 'Search' - the checkbox "Hide probably good edits" becomes checked again.
Note: without Preferences-Recent changes "Show only likely problem edits ..." option is not enabled, Contributions page options work as expected.