Hi Willi,
It is possible, that you have set the search to use the Roboto font under the typography options – or more likely I believe one of the filter features (I think the select/multiselect with search) has by default the Roboto font set with a fallback to Helvetica – maybe it is matching that.
The font-face is definitely not enqueued though, so that does nothing at all. If you want to see which fonts were actually included and rendered, you can do that via the developer tools: https://i.imgur.com/s1QVL9h.png
