Wordpress - I changed the permalink structure and the posts got error 500 (Internal Server Error)

Question

Opa, I changed the structure of my permalinks to /blog/%postname% as in the image below:

The post opens normally, curious that in Google Console and browser the error 500 is flagged and points the error in index:1 as in the image:

I’ve tried everything and nothing! Does anyone know how to fix this? It’s a server error or is it in my code/plugins?

Note: in place the error does not happen...