I am sorry but your link https://easyupload.io/e8b00k asks to download something, which I will not do.
If this is a screenshot, please provide a link to a screenshot we can look at online, without risking to download something we wouldn’t want to.
You probably mean the Page cache is not detected but the server response time is OK notice, rather than In site health , Page cache not deducted error is showing.
That warning clearly explains what it looks for:
Page cache is detected by looking for an active page cache plugin as well as making three requests to the homepage and looking for one or more of the following HTTP client caching response headers:
cache-control, expires, age, last-modified, etag, x-cache-enabled, x-cache-disabled, x-srcache-store-status, x-srcache-fetch-status.
Median server response time was N milliseconds. This is less than the recommended 600 milliseconds threshold.
No client caching response headers were detected.
A page cache plugin was not detected.
So, probably you do not use a plugin that is “supported” nor does the service you use add any of those headers.
As example on a site I use LiteSpeed Cache (got to disable it soon because it is useless) and, I get the same warning – even though of course page cache is enabled.
