It takes time. You can win some backlinks from the desired country-specific directories or so. This will improve your chance of ranking in those countries.

Setting the meta description globally in Rank Math is a straightforward process. Here's how you can do it:

1. Log in to your WordPress dashboard.

2. In the left-hand menu, click on "Rank Math" to access the Rank Math settings.

3. In the Rank Math settings, click on "Titles & Meta" in the sidebar.

4. Under the "General" tab, you'll see a section labeled "Homepage." In this section, you can set the meta description for your homepage.

5. To set the global meta description for all your pages and posts, scroll down to the "Global Meta" section. You can enter your desired meta description in the "Global Meta Description" field.

6. After entering your global meta description, make sure to click the "Save Changes" button at the bottom of the page to save your settings.

This should set the meta description for your entire website. However, please note that individual pages or posts can still have their own meta descriptions, and these can override the global setting. So, if you've set a meta description for a specific page or post, Rank Math will use that instead of the global one.

Regarding the issue you mentioned about Rank Math not properly setting meta descriptions for specific categories within the Portfolio area, it might be a more specific problem that requires investigating your site's setup and how Rank Math interacts with your theme or other plugins. Since you mentioned that Rank Math support is not very responsive, you may want to try reaching out to the WordPress community or forums for assistance, or consider seeking help from a WordPress developer who can delve deeper into the issue.

Remember to regularly check for updates in Rank Math and your WordPress plugins, as sometimes issues can be resolved through updates.