I just completed the Agile Tactics Array quest (contribute 60,000 xp in winning games), but instead of completing the quest, it reset my progress back to 0. I got a chest for completing it, but my progress went back to 0 of 60,000.
Mission: Agile Tactics Array quest is “Repeatable”.
This can be seen on the Mecha Tyrael screen when you hover of any of the seven quest lines. It is also blue colored in the Quest Log compared to the yellow color for the first two quests.
Click on Special Event button at the top of the screen to change to a different quest line.