Pwm_input driver not working PX4 v1.13.3

I’m working with PX4 v1.13.3 and I’m trying to read a PWM signal from FMU_CAP1 (AD&IO port, second pin). I’ve tried to use the pwm_input driver but I get the following error when I start it:
INFO [pwm_input] timer/channel alloc failed (-16 -16)

I’ve tried to find out where the issue was but I did not succeed. Does anyone manage to solve this issue ?