Motor Testing DSHOT no response

Hello everybody,

I am switching from ardupilot to PX4 but I am struggeling to setup my DSHOT ESC. That means that my wiring already worked, i.e. Telemetry and Ground cable connected to TELEM1, and Signal cables connected to the Signal pins of the Output Rail (see this image of the Mini Carrier Board).

It is a Fettec 65A ESC and in the Actuator Tab I set AUX 1-4 to DSHOT1200 and assign Motor 1-4 to AUX 1-4.
I also set DSHOT_TEL_CFG to TELEM1.
I disabled MAVLINK on TELEM1 by setting MAV_0_CONFIG to disabled.

When I power on the ESC, I get two beeps (in contrast to five beeps with the working ardupilot setup)

I do not have a RC setup, would that be an issue?
No matter what I do, the motors will not spin.
What could be the problem? Is there some hidden safety switch?

Thank you for your help.