Slow website loading if proxy is turned on

Hello! I have noticed an issue with my website. If my DNS record is proxied to my website with CF, the load speed drasticly slows down. This is not an issue if I want to download a singular file, but when there are multiple ones at the same time; for example a page containing 4-5 images.

As you can see the download speed is still good, but for some unknown reason my browser waits a lot on the server.
If I turn off the proxy, everything loads perfectly.

Should we guess the domain?

The domain is, but I have multiple domains and all have the same problem.

There is not much content at that domain but it loads in less than a second

A post was split to a new topic: Performance concerns