We've been investigating the lag and are asking those of you who can, to provide a video recording of the problem which we can review. Please provide a link to the video through Support. Hopefully, this will help us track down any issues.
We've discussed the lack of stamina rewards in the newest Epic Quests and have decided that the quests are fine as is. Not all Epic quests give stam rewards and this quests gives the correct XP for the effort expended. We shall not be changing anything in this release.
Thank you for the feedback in this matter but we feel it is fine as it is.