Question about DJI Intelligent Flight Battery

When I put the battery into the 4-way charging station of the Fly More Kit, the battery is simply not charged. Only a red LED lights up on the charging station. I have also tried to initialise charging by pressing the button on the battery for a long time, but that doesn't work either. Direct charging of the batteries via the main charger (where the remote control can also be charged) does not work either. Can anyone help me? What is the problem and how can I fix it? Thanks for any helpful tips.