WordPress permalinks not redirecting in my new theme

Hi, I’m using /%postname%/ as a permalink structure.

In the default theme everything works fine but in the new theme, default link ‘?p=123’ does not redirect to the ‘Post Name’ link, while both links are working at the same time.

To clarify further… https://www.myblog.com/?p=123 does not redirect to https://www.myblog.com/some-blog-post. Both links are working, but no redirects are applied. This problem only occurs when this specific theme is activated while it works perfectly on all other themes.

Any ideas?