重现步骤

1. 打开代码片段，使用npm按照tdesign和构建npm
2. 在iOS手机的skyline渲染模式下打开小程序
3. 点击左上角显示popup
4. 会发现在canvas的区域有一块黑色

已知可能原因：

1. popup背景设置了backdrop-filter: blur(20rpx);
2. popup的overlay为fixed定位

两个设置导致冲突

现象视频：https://private-user-images.githubusercontent.com/57854506/544092656-d84b735f-42c7-4e28-947e-142cb3b6426f.mp4?jwt=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.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.2MFGcFerpfkbIYSlir5cW9fIqkxv4z5q7Jb_YjVOSHo