Hello, @Oliver Theiß,
First of all, I didn’t touch anything on your site.
Secondly, you wrote in your second point: “I have the problem that two times ratings is displayed….”
So it was not clear enough that the complete review box or the stars are showing twice and that is why I provided you the Custom CSS to remove the stars only.
But as you explained it now clearly, I have prepared another Custom CSS for you, for removing the Complete Review Box which is showing twice.
Please copy and paste the below-given CSS code to XStore >> Theme Settings >> Theme Custom CSS >> Global Custom CSS, and check back your site after removing the browser cache.
.single-product div#reviews:nth-child(2) {
display: none !important;
}
Regards 8Themes Team.