ESP32 pulsed PWM at low frequencies

The problem is that I'm expecting a low frequency (1.25khz) continuous square wave when writing to the PWM output of the ESP32 and what I get is regular/irregular pulsed PWM triangle wave with a 125hz pulse rate (enough for the human eye to see it as flickering.)

Is there any way around this?

I've tried the config below for it:

ledc_timer_config_t ledc_timer_D = {
    .duty_resolution = LEDC_TIMER_15_BIT,
    .freq_hz = 1250,                     
    .speed_mode = LEDC_HS_MODE,          
    .timer_num = LEDC_HS_TIMER_2,          
    .clk_cfg = LEDC_USE_APB_CLK,              
};

The output:

I've tried this with the low speed as well and got the same issue, if not an issue when compiling through VS Code IDE.

From the drawing you show in the graph, it seems you are not using a good sampling device and you are sampling at a low rate too. The poligonal shaped traces of the signal indicate that probably you are sampling at the same frequency of the pwm signal or even lower. I should recommend you to oversample (let's say 16 times faster) to see properly shaped square pulses.