Answer by Michael for str_replace remove words from title

the_title() will directly output the title - for your purpose in a string manipulation, you need to use get_the_title()https://developer.wordpress.org/reference/functions/get_the_title/

you also have some php syntax error;

try to use:

<?phpecho str_replace( "(Blu-ray)","&nbsp;", get_the_title() );?>