I dont remember which tasks. Refreshing didn't helped, but after some time when I completed a task I got 2 new tasks instead of 1, and that goes until I got all 6 tasks back.
Relogin also doesn't help (I tried it the first time it happened)
And I dont know if tasks would add on their own after some time, I waited around a hour first time that happened and nothing changed.
EDIT: I think it has something to do with my connection, it sometimes just stop working for 15-30 seconds.