I just checked out one of my posts on Schema tester tool and was surprised to find it has 3 errors.
I have shared the URL on Google and I request you to please check any articles and see where the error is coming from. I am panicking.
P.S. I have not disabled GP schema markup or anything and the Yoast plugin is at the latest version (it had introduced schema markups in some versions I think.
Those errors are coming from the JSON+LD markup that Yoast SEO is added. You likely need to configure some things in the plugin if you’re using Article.