This is [Hero Cantare] CM Liddie!
We would like to notify a known issue after the maintenance on May 17th PDT.
We found an issue that the [A], [S], and [SS] button which allows to select many Artifacts by one tap are malfunctioning.
Currently, the issue is temporarily aided by removing the buttons at the Artifact Upgrade scene.
The bug will be fixed during the maintenance on May 24th PDT.
We are sincerely sorry for your inconvenience and thank you for your patience.
Hero Cantare Team