在任何类型的速度测试站点上都说我的图像没有应用缓存

on any sort of speed test site it says that my images do not have a cache applied to them.

这不是这个意思。屏幕截图显示他们的新鲜度寿命短，建议超过1周。

That isn't what this says. The screenshot says they have a short freshness lifetime, and longer than 1 week is recommended.

您的设置为 max -age = 86400 仅24小时。

Your setting of max-age=86400 is only 24 hours.