three.js: Two mesh with Muti-Materials set same renderOrder value, the z-order is not correct?

Description of the problem

I create two mesh with same renderOrder.

var circleGeometry = new THREE.CircleBufferGeometry(radius, segements);                                                                                                                                                                 
var ringGeometry = new THREE.RingBufferGeometry(radius, radius + ringWidth, segements);                                                                                                                                                                 
var cellGeometry = null;
  
//...

var circleMaterial = new THREE.MeshBasicMaterial({                                                                                                                                                                                                                                                                        
  map: texture,                                                                                                                                                                                                                                                                                                         
  // wireframe: true                                                                                                                                                                                                                                                                                                    
});                                                                                                                                                                                                                                                                                                                       
var ringMaterial = new THREE.MeshBasicMaterial({                                                                                                                                                                                                                                                                          
  color: 0x000000,                                                                                                                                                                                                                                                                                                      
  vertexColors: THREE.VertexColors,                                                                                                                                                                                                                                                                                     
  // wireframe: true                                                                                                                                                                                                                                                                                                    
});
                                                                                                                                                                                                                                                                                               
cellGeometry = THREE.BufferGeometryUtils.mergeBufferGeometries([circleGeometry, ringGeometry], true);                                                                                                                                                                                                                     
var mesh1 = new THREE.Mesh(cellGeometry, [circleMaterial, ringMaterial]);                                                                                                                                                                                                                                                 
scene.add(mesh1);                                                                                                                                                                                                                                                                                                         
mesh1.renderOrder = radius;                                                                                                                                                                                                                                                                                               
var mesh2 = new THREE.Mesh(cellGeometry, [circleMaterial, ringMaterial]);                                                                                                                                                                                                                                                 
mesh2.position.x += 2;                                                                                                                                                                                                                                                                                                    
mesh2.renderOrder = radius;    
                                                                                                                                                                                                                                                                             
scene.add(mesh2);  

The result was not correct, see screenshot! 

Three.js version

• r94

Browser

• Chrome

OS

• macOS

Hardware Requirements (graphics card, VR Device, …)