after html2canvas is converted to canvas, some iphone models are blank.
Test models and results:
1.iphoneX system 11.3.1 Blank
2.iphone6p system 9 Blank
3.iphone6s system 11.3 normal
4.iphone6 system 12 normal
5. Android 7 is normal
6.iphone7 ios11 blank

the key code is as follows:

              let node = document.getElementById("proposal");
              let nodeImage = document.getElementById("proposalImage");
              html2canvas(node,{
                  height: node.offsetHeight || node.scrollHeight || node.clientHeight,
                  width: node.offsetWidth || node.scrollWidth || node.clientWidth,
                  x:0,
                  y:0,
                  useCORS:true
                  }).then(function(canvas) {
                    canvas.style.width = "100%";
                    canvas.style.height= "auto";
                    node.innerHTML = "";
                    nodeImage.appendChild(canvas);
    
                  });

Google has tried a lot of configurations, but they are still not solved. I am still exploring. I hope someone has stepped on the pit to help me. I have been desperate for many days. Thank you all