Why is LM3429 LED driver demo board malfunctioning?

[Flyback]

Hello,
We used the LM3429 evaluation board (Boost LED driver) with PWM dimming of LEDs and it mis-functions..why?
The Board runs OK when it is not being PWM dimmed, and gives the correct 153mA of LED current, but when we apply the PWM dimming signal, the error amplifier output voltage (“COMP” voltage) rails high and the LED current rises to 190mA. (190mA when it is in an “ON” interval of PWM dimming)
Why does the error amplifier get railed high when PWM dimming is taking place?
LM3429 evaluation board:
https://www.ti.com/lit/ug/snva404b/snva404b.pdf

LM3429 datasheet:
https://www.ti.com/lit/ds/symlink/lm3429.pdf
Spec of our LED driver in use on the LM3429 evaluation board..
Vin = 12V
Iout = 0.153A
V(LEDs) = 54.4V (16 leds in series)
Off time = 656ns (F(sw) = 332KHz)

We changed components on the board to suit our spec, which is as follows..
R8 to 5k1, R6 to 0.22R, R9 to 3R3, R10 to 75k, and L1 to 100uH

 

[crutschow]

Did you use their design equations to calculate all the values for the components you changed?
What are the characteristics of the PWM dimming signal?

 

[Flyback]

The components, as you can tell from above, are fine, and indeed it runs fine when NOT being pwm dimmied..the problem only happens when its pwm dimmed....the pwm dimming signal is 500Hz and 50% duty...but any pwm makes it malfunction...it shouldn't make a difference because the block diagram shows it should prevent the comp pin cap from discharging during pwm OFF intervals.

 

[crutschow]

The components, as you can tell from above, are fine, and indeed it runs fine when NOT being pwm dimmied..the problem only happens when its pwm dimmed....

No, I can't tell from above that the components are fine, and I certainly can't deduce that the components are fine just because it appears to work when not being dimmed.
The fact the dimming doesn't work would strongly suggest an error in the circuit and the likelihood that one or more of the component values may be marginal, causing the observed failure when dimming is tried.
It's illogical to say that the circuit is not working properly but has no error in the design.