Help: Title Tag does not change in SERP.

Hello, how are you?

Guys, I'm on a client SEO project and I have the following problem:

I use Wordpress as CMS, with SEO Yoast installed and configured, with Search Console already installed and integrated with Yoast and simply the Title Tag of the site on Google SERP does not change. In the Site yes changes normally, but in SERP always appears the prefix "Campinas", as print attached.

The point is, I've done everything I had to do, I've looked at the robots, I've resubmitted the urls to be crawled by Search Console, I've checked the WP General tab, I've resent the Sitempas, I've changed the tag several times title on SEO Yoast and nothing, I can't get Google to see the correct URL.

The strange thing is that if I type a more specific term by region, as in the attached print, "Unicursos SJC" the title tag has already been changed, but when I search for the site name only it has not changed.

Has anyone ever experienced this? If so, could you tell me a way I can work to change?

I thank you all for your attention.

If you're manipulating your site title with something that google deems to be irrelevant or overly spammy, they may just ignore it. Ie. if you're Joe's Plumbing and your site title is: "Best Plumbing Denver | Denvers Best Plumber | Joes Plumbing" they may just use on-page elements to make an educated guess on what the title should be.