How to Redirect https://example.com to https://www.example.com

Try to set the WordPress Address and Site Address under Dashboard > Settings > General to https://www.example.com

That worked for me.

ONE tip: backup .htaccess before you try this

https://www.blog.web6.org/with-or-without-www-wordpress-blog/

https://theindexer.wordpress.com/2009/02/12/redirect-all-users-to-access-your-site-withwithout-www-prefix/