Thanks, @Benny1337
Unfortunately, because my husband did aid work in an African nation, which is now highly unstable, they require a police certificate from there. There was no heads up from NVC - they accepted what we provided to become DQed after all. The certificate can't be obtained - we tried multiple times.
Anyway, all the rules of everything/processes are detailed in the Foreign Affairs Manual (FAM), and there are some workarounds that we are pursuing. π₯΄