Thanks! Was looking at the wrong php file
I’m really happy about the fact that the site is loading fast for other users :)!
I tried loading the site from another machine that has another IP. The loading went a little faster but still not as fast as it should be/ as GTmetrix and other speedtests show.
I will contact the hoster to see if they know the cause. Thanks for the help!
Thanks for the response!
The tests show an really nice loading time. Unfortunately the real/actual loading time is slower. I am really wondering how the site is getting these good numbers from tests while the actual loading speed is terrible.