What did you expect to happen? That the defined Yoast Seo Meta Title shows in Search Results in Search Engines
What happened instead? It shows just the wordpress page title as Meta Title which is not very useful
How can we reproduce this behavior? Just google on google.at for tischler graz and look on 3rd page you find Tischler Graz as Page Title
Can you provide a link to a page which shows this issue? http://www.tischlergraz.at
I have this issue also on other domains, and other themes, the OUTPUT Meta Title should be the customized one in yoast plugin and not the page title.
The google cache for your page shows another title than what you currently have – see the cache here – so it might update when it has re-crawled your site. To improve how fast Google crawls your site, please follow the suggestions in this post by yours truly.