Since xunit 1.56, the 2 following fields are not saved properly:

...
Skip if there are no test files [ ]
Fail the build if test results were not updated this run [ ]
...

Ticking/not ticking the checkboxes has not effect on saved values (hardcoded to false):

<xunit plugin="xunit@1.56">
  <types>
    <JUnitType>
      ...
      <skipNoTestFiles>false</skipNoTestFiles>
      <failIfNotNew>false</failIfNotNew>
      ...
    </JUnitType>
  </types>
</xunit>

Other fields are still behaving properly.