[Gelöst] Wrong language loading first

Background of the issue:
I am trying to ensure that when I enter the page through Google results, it opens in Greek, which is the default language. The issue can be seen at versteckter Link.

Symptoms:
When accessing the page via Google results, it opens in English instead of Greek.

Questions:
Why is the English language loading first instead of Greek when accessing the page through Google results?
How can I set the Greek language to load first as the default?