After an evaluation from Google regarding the readability of the website, they may come to the conclusion that the text size is too small and can not be adjusted according to the type of mobile and mobile screen size.
This can result in the website in the search result coming further down in the results, or simply not appearing.
To fix this I have deleted the general text size of the website in the <body> tag. This will result in that not everyone seeing the text size the same way. It will now adjust to how each screen is set. We thus no longer have 100% control over how each individual sees the website (but it should still be about the same). Now each individual can change the size by enlarging or reducing the text themselves.