Hello,

I have logged into your website and created a new product and marked it as New for a time and it is appearing in the Neue tab.

Screenshot for Clarification: https://gyazo.com/4f7ffb86328b00950513db5a8d6d8814

Which clears that the issue is not from our theme. It seems that you have imported the products that are causing the issues.

Please try recreating the products and mark them as new then check back.

Best Regards