Our page has a 100 rating for Desktop in Google Page Insights. This is expected because the page only has the word "Test" on it.
However, in the screenshots below (where Page Insights shows the loading process) the first screenshot is always empty. In the second screenshot, the word "test" is visible.
From my browser, the page loads instantly (as expected) even with a slow connection.
This is a strong dedicated server with 16GB of RAM (although this shouldn't come into play at all).
What could be causing this problem for Google? Could it be simply a matter of geolocation or something similar? We are using Cloudflare for DNS management.
How can I test and remedy this problem?