More info would be helpful.
Is this a value list that no longer correctly displays data or is it that once you select a value from the value list, the expected data is not looked up?
I'd guess that it's the value list that has the issue and thus it may be this known bug:
For More Information see: VALUE LISTS NOT WORKING - when show values only from second field is selected
This is one of many acknowledged bugs that can be found in the Known Bug List thread here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: https://www.dropbox.com/s/jt09b82i0xijbu3/FMP%20Bugs.zip