Meteor 75 pro arming

I’m new to FPV and have the following problem. I own a RadioMaster Pocket and a Meteor 75 Pro.
Yesterday I flew normally and everything worked perfectly.

Today I start the drone and the RadioMaster, plug in the Lipo, and when the drone is not armed it suddenly beeps continuously. Beep-beep-beep-beep…

When I arm it the beeping stops, but the motors don’t spin at idle. However, when I move my stick left and right, the individual motors spin as if it’s steering.
Unfortunately I can’t find a solution. Can you help me?