I'm noticing some quests having differing numbers of players completed on the game screen and then when viewed on your profile. Also, some have different release dates and I'm not talking about the strange 1969 release date.
Looks like you're right. The quest I was looking at now has the correct release date, complete date, and number completed on profile. It matches with the one seen on game.
I've just never noticed the release date differ from profile to game page (aside from the Jan 1, 1969 one, which I assume is some set "1st date" given by the server or code.) So this was something different. But, it's correct now.