The Bug
Daylight Saving Time recently ended in the United States. Soon afterwards Magia Record players on the English Server can no longer progress in the game.
When players prepare a magical girl team for a battle in MagiReco, they're required to select a magical girl from the support list. It appears that after 8 AM local time, the game server begins to return an empty Support Select list, preventing players from entering battle.
As of writing, neither Developer f4samurai nor Publisher Aniplex of America have officially address the bug, or compensations to the affected players.
File a Support Ticket
As Producer Masaki Sato explained in the GamePress' Magia Record Producer Interview, the best way for players to reach the developers is using the official Feedback Form to file a Support Ticket:
Workarounds
Until the DST bug is fixed, the community on Magia Record Subreddit has suggested several workarounds: