Validation Groups Different Between 7.8 and 7.7

validationGroup "values" seem to be treated differently in version 7.8 vs 7.7. I have a form with 2 validationGroups labelled: "Implemented" and "Not Implemented" (code attached). They work correctly in 7.7 (Effort Minutes field is required for Implemented button; Comments field is required for Not Implemented button). But in 7.8, the required message displays for both fields when Implemented is clicked, and neither fields when Not Implemented is clicked (though the form does not submit). I resolved the issue by replacing "Not Implemented" with "Not_Implemented". What has changed in 7.8 to cause this behaviour?

SAILExample_ValidationGroup.txt

OriginalPostID-138053

OriginalPostID-138053

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