Sitename is not displayed in Seo title of google search result

Hello @johnpetsa,

Thank you for contacting the support and sorry for not following up quickly and any inconvenience that might have been caused due to that.

Google shows the title/description tag according to the search intent.
https://rankmath.com/kb/different-meta-title-and-description/

The best you can do is optimize your meta tags to try and match the intent of the search/keyword.

You can read more about it here
https://support.google.com/webmasters/answer/35624?hl=en

‘Why the search result title might differ from the page’s <title> tag’ this section.

Hello~ thank you for your reply^^

↓↓One of my website URL with the problem↓↓

I saw the source code(Ctrl+U) of the URL, the <title> is fine(my sitename is still right after the title). On the other hand, some of my website URL is still fine in google search that my sitename is displayed after the title, but the fundamental setting in the source code of both URL are more or less the same.

↓↓The normal URL of my website in google search↓↓

Also I found that some of the other website URLs are facing the same problem in google search.

↓↓One of my website URL with the problem↓↓
https://www.tilesupdeco.com/%E6%9C%A8%E7%B4%8B%E7%A3%9A%E5%85%A8%E6%94%BB%E7%95%A5/

↓↓The normal URL of my website in google search↓↓
https://www.tilesupdeco.com/%E4%BB%80%E9%BA%BC%E6%98%AF%E5%9C%B0%E8%85%B3%E7%B7%9A%E5%83%B9%E9%8C%A2%E5%8F%88%E6%98%AF%E5%A4%9A%E5%B0%91/

Hello @johnpetsa

As mentioned earlier, Google is showing different SEO titles and rewriting them on its own:
https://www.searchenginejournal.com/google-is-rewriting-title-tags-in-serps/416793/

There is hardly anything you can do about that.

Hope that clears the confusion and helps. Thank you.