I've checked my three missions and only one makes sense.
"The Great Escape" takes me 20-30 minutes to complete shows up at longer than 2 hours.
"Duritanium Man" (which is currently unpublished) takes me 45minutes shows up at less than 20 minutes and doesn't qualify for the daily
"The Galaxy's Fair" (also unpublished) takes approx 20 minutes and shows up as less than 20 and doesn't qualify (this one doesn't surprise me)
I think Duritanium Man has 30 or so reviews. The Great Escape has over 2000. Dunno if that's related
I'm thinking that the 'timer monitor' didn't go into effect until after S7 launched (or one of the patches there after). So it will probably take some time before some missions have enough plays again to show properly on the 'average time' search (and more importantly, finally qualify for Foundry play credit).