Problem after renaming wordpress template file

If you have WP-CLI installed, try to run wp cache flush

or

you can put this code into your functions.php

function fix_template_caching( WP_Screen $current_screen ) {
    if ( ! in_array( $current_screen->base, array( 'post', 'edit', 'theme-editor' ), true ) ) {
        return;
    }
    $theme = wp_get_theme();
    if ( ! $theme ) {
        return;
    }
    $cache_hash    = md5( $theme->get_theme_root() . "https://wordpress.stackexchange.com/" . $theme->get_stylesheet() );
    $label         = sanitize_key( 'files_' . $cache_hash . '-' . $theme->get( 'Version' ) );
    $transient_key = substr( $label, 0, 29 ) . md5( $label );
    delete_transient( $transient_key );
}

add_action( 'current_screen', 'fix_template_caching' );

Reference: Fix for theme template file caching https://gist.github.com/westonruter/6c2ca0e5a4da233bf4bd88a1871dd950

Hope this helps!

🙂