Cross Validation Rules stopped working

What can cause Cross-Validation Rules to stop working?

We set up rules years ago when we implemented, and they have been working.   A user inadvertently created a combination of segments that the cross validation should have prevented.  They were able to select it, save it, and post the journal.  If I look at fnd_flex_vdation_rules_vl , the rules are enabled and have no end date.  Fnd_Flex_Validation_Rule_lines shows that all the lines of the rules are also enabled.

Any help on this is greatly appreciated!