Flipsky Vx3 connected with Flycolor Flydragon 150a

Hi, I try to setup a system of a Vx3 remote and the Flydragon 150a ESC but I got a little bit confused with the output of the Vx3 and the input of the Flydragon. Technically the Vx3 stated it has a PPM output (which I used for the connection towards the ESC) and the Flydragon requires a PWM input. But I saw some threads about exactly this combination. Sometimes the output of the Vx3 is described as PPM/PWM, which makes me think it should work (since the PPM is only one channel).
I tried the several ESC modes of the remote (FSESC, VESC, NO VESC), but the result is still the same: I can’t calibrate the throttle input at the ESC. Interestingly if I disconnect the receiver and reconnected it again at full throttle the ESC enters the Programming mode. If I’m not at full throttle the programming mode is not entered at reconnection. So the communication is somehow there.
I would really appreciate any advice or hint to any existing thread. Many thanks!

PWM and PPM in this case is exactly the same

If it does not work, and your Rx and Tx are set to output PWM, the ESC not calibrating can basically only be due to wrong timing or incorrect voltages

How did you wire everything? Where is the 5V power coming from? How many wires does the ESC signal cable have?

Regarding timing, if the ESC is programmable try to tweak the accepted throttle range there
Or see if the remote has an option to change PWM timing parameters

Never touched one of those ESCs, but what you describe is pretty much standard for most non VESC ESCs.

To calibrate you power up at full throttle, after the beep you go to zero throttle and after that beep calibration is done and saved.

If you do not power up with full throttle it goes directly into operation mode.

Does your ESC do beep codes at startup?
If yes, read the manual to find out the code for the beeps you are getting.