Hi Holotable Heroes,
About a month ago, we received several reports that some players were able to add zetas and relics after the lock in Grand Arena. In investigating those instances, we found that it is possible to delay the roster lock mechanism. Currently, a player's roster is locked when they log in to the game (that means starting the game and seeing the loading screen) or when they visit the Grand Arena landing page after the preview phase has expired. This is currently driven by your device communicating with our servers, and, in certain circumstances, allows relics, zetas, or new units show up after the period that should be "roster locked". We are working on a fix that will move the roster lock to be when the player joins the event, locking whatever players had set at that moment.
We've discovered the root cause of this issue and are working on a fix. Our hope is to roll this fix out in the next two weeks. We did not alert the community about it earlier, for fear that it would cause a spike in the behavior. Some players, with the introduction of GAS, have exposed the issue and we're letting you know that we a) know about the issue and b) have been working on a fix. We posted this issue to the if you want to monitor its status.