Particle system MinMaxCurve problem

I have a specifc problem with particle system , I’m controlling the particle system via script , the problem comes up when I try to edit any MinMaxCurve in any module as shown below :

using System.Collections;
using UnityEngine;

[RequireComponent(typeof(ParticleSystem))]
public class PSTest : MonoBehaviour {

	ParticleSystem MyPS ;

	void Start () {
		
		MyPS = gameObject.GetComponent<ParticleSystem>();

		ParticleSystem.MainModule MyPSMain = MyPS.main;

		AnimationCurve ACTemp = new AnimationCurve (new Keyframe[] {
			new Keyframe (0, 1) , new Keyframe (1, 0) });

		MyPSMain.startSize = new ParticleSystem.MinMaxCurve ( 1 , ACTemp ); 

	}

}

when I try script in the editor it works fine and no exception is thrown but when I run the project on android device the application exit and stop working after some tests I found that this line is making the issue :

MyPSMain.startSize = new ParticleSystem.MinMaxCurve ( 1 , ACTemp ); 

So I try something else :

using System.Collections;
using UnityEngine;

[RequireComponent(typeof(ParticleSystem))]
public class PSTest : MonoBehaviour {

	ParticleSystem MyPS ;

	void Start () {
		
		MyPS = gameObject.GetComponent<ParticleSystem>();

		ParticleSystem.MainModule MyPSMain = MyPS.main;

		AnimationCurve ACTemp = new AnimationCurve (new Keyframe[] {
			new Keyframe (0, 1) , new Keyframe (1, 0) });

		ParticleSystem.MinMaxCurve SizeCurve = MyPSMain.startSize;
		SizeCurve.curveMultiplier = 1;
		SizeCurve.curve = ACTemp;

	}

}

but what happens is the value of curve constant is working but the curve itself isnt assign to the start size , I though that I was taking value by reference when doing that , but when I debug I noticed that the start size have a value of null for both Min and Max Curve

Hi, please report a bug for this issue, using the first script: Unity QA - Bug Reporting - Unity