Yoast SEO-Plugin

We have installed on our website Yoast SEO plugin and entered Title Tags and Meta Descriptions for all subpages. Now we have found out, however, that the data is not transferred in the source code, for example: https://www.via-verde-reisen.de/reiseland/georgien/

After some trial and error, we have now found out that we can enter the meta data via a detour in which we as the above-mentioned page in the browser, “Edit Category” button and then fill out the SEO titles and SEO description. This we have already done on the main pages. However, we would therefore all sides revise once more, if we consider the Meta Tags now enter in this way.

Does anyone know another solution and can tell us where the fault is? Are the plugin and theme used maybe not compatible? Thanks in advance for your assistance!