Yes, it is language!
Obviously, geocoding folder items can not be merged when system language is Turkish on MacOS.
These forums are not within Tableau Customer Support and answers supplied are done by volunteers like you and I (who have paying jobs that are a priority to helping out in the forums), not a big team of dedicated paid Tableau support staff. There are Tableau employees from different areas within the organization who come here and answer questions and there is a small forum admin staff who help answer questions but it's really the Tableau community users who answer the majority of the questions.
If someone here in the forums cannot help answer your question then you should contact Tableau Support and open a case. That is the best way to get issues into Tableau and find the attention of the appropriate internal personnel.
Hello Toby Erkson,
I spent some time seeking for a page that I can open a case but since I couldn't find one, I've used this forum. Actually I would be thankful if you can lead me to such a page.
Let's hope this topic helps other users.
Thanks Toby Erkson. On the page following to your instructions there are still recommendations but also one additional button which I was missing:
I will use it from now on if I need official support.