Elektron Model Cycles similar FM Feedback effect

Hi!

I'm trying to apply FM feedback, but I'm not sure if I'm getting it right or I'm missing something.
I'm trying to achieve a feedback effect like the one from Elektron's Model Cycles... Here is a small part of a video that shows how the Model Cycles feedback sounds:

https://youtu.be/csYWGW7Gwo4?t=459

My implementation makes the pitch change sometimes and adds tones that are lower than the fundamental. Unlike my implementation, the Model Cycles feedback doesn't seem to change pitch and it doesn't seem to add tones lower than the fundamental, it just adds overtones (I'm not sure though, since I don't own one).
1.- Does anyone knows how can I achieve the Model Cycles feedback effect? (No tones lower than fundamental, just overtones).
2.- Is there different methods of applying FM feedback that results in a different sound?

Here is a patch with my attempt of FM feedback:

Thanks!!