I am having the same issue with select drop down boxes not saving, but my editor is fine.
I copied the sample form and snippet from the provided tutorial into a new document and tested.
http://rtfm.modx.com/extras/revo/formit/formit.tutorials-and-examples/formit.examples.simple-contact-page
The validation will work, however the checkboxes and select drop down default to their original unselected values. You must then select them again. I figured after reviewing the section "FormIt.Handling Selects, Checkboxes and Radios", I would have a clearer understanding, but this does not discuss re-populating the fields, it only explains the validation, which is separate feature.
I assume I may need to add the 'FormItIsSelected' and 'FormItIsChecked' somewhere to run the snippet, but no luck with that either.
I am also running [[!formItRetriver]] at the start of my form, but it's only working for text input fields.
Is there a way for select, checkboxes, and radios, to actually retain their selected values? I am working on a long survey and need these values saved on validation refresh.