I’ve finished my missions 1 hour before the refill, logged in after two hours and found out that “Missions refill in 2 hours”. Well, this is weird 
EDIT: OK. I restarted the game and guess what? They actually refilled. Still a bug, tho, because I had to relog to see them.
Something very similar happened again. Missions seemed like they didn’t refill and even restart didn’t help. But when I played one match it turned out missions actually refilled, even more, xp earned in this match counted towards them. So, it’s like they are here, but aren’t shown