We have previously been using the vesc 4.12 with the custom firmware for outputting PPM signal to use with an external steering servo, but after moving to the vesc6.4, it seems like the hardware does not output the ppm signal, even after flashing with the firmware. We have verified that there is no signal output through connecting a scope between the signal and GND pin, without any result.
Is there any reason why this should not work?
Can you give the latest version of vesc tool and the firmware a try? I just made a fix, so hopefully it works now.