Zephyr PWM: pwm_nrfx.c - Limitation with NCS driver? "Incompatible period."

Question

I am working with the nRF54L15 to create a driver for a peripheral which is controlled by two PWM signals.

My driver relies on the Zephyr PWM driver which goes back to your implementation of it in pwm_nrfx.c. Everything works fine except one case, and I don't understand this limitation.

If I command one of the signals to pulse at 100% duty cycle and I leave the other one off, if I then try to set the off PWM signal to a non-static setting (1-99% duty cycle) then it results in the "Incompatible period." error. [SDK\zephyr\drivers\pwm\pwm_nrfx.c, function pwm_period_check_and_set()]

Both of my PWM channels are set to the same frequency (PWM_USEC(100)) so I don't understand what the problem is here. Is the driver optimizing the PWM period to something other than my setting when I command the one signal to 100% duty cycle? And so when I set the other signal, the PWM driver is actually running a different period than my setting? I could understand this for power savings, but I need to somehow deal with this limitation.

Relevant code:

struct tps923653_config
{
    const struct pwm_dt_spec en_pwm;  // EN/PWM pin  (High=Always On, Low=Device Disabled, PWM=PWM Dimming)
    const struct pwm_dt_spec adim_hd; // ADIM/HD pin (High=PWM Dimming, Low=Hybrid Dimming, PWM=Analog Dimming)
};

/* Startup state: */
(void)pwm_set_pulse_dt(&config->en_pwm, 0); // Set low
(void)pwm_set_pulse_dt(&config->adim_hd, config->adim_hd.period); // Set high (100% duty cycle)

/* Produces the error: */
err = pwm_set_pulse_dt(&config->en_pwm, config->en_pwm.period/2);
if (err)
{
    LOG_ERR("Failed to set EN/PWM: %d", err);
    return err;
}

Relevant devicetree overlay:

&pinctrl {
	pwm21_default: pwm21_default {
		group1 {
			psels = <NRF_PSEL(PWM_OUT0, 1, 11)>,
			        <NRF_PSEL(PWM_OUT1, 1, 12)>;
		};
	};
};

&pwm21 {
	status = "okay";
	pinctrl-0 = <&pwm21_default>; /* Only default, no low power config */
	pinctrl-names = "default";
};

/ {
	ir_driver: tps923653 {
		compatible = "indesign,tps923653";
		status = "okay";
		
		/* EN/PWM and ADIM/HD pwm configuration */
		pwms = <&pwm21 0 PWM_USEC(100) PWM_POLARITY_NORMAL>,
			   <&pwm21 1 PWM_USEC(100) PWM_POLARITY_NORMAL>;
		// pwm-names = "en-pwm", "adim-hd";
	};
};

Let me know if I am just outside of the scope of expected use of the pwm_nrfx.c driver and need to make something custom for my application, but I feel like this is may be a bug.