RSS not updating, no matter which plugin I try

Under the hood the RSS widget uses fetch_feed(). From the codex:

fetch_feed caches results for 12 hours by default. You can modify this by modifying the time interval via the filter wp_feed_cache_transient_lifetime.

So you will need to add this code to adjust the expiration:

function danniee001_feed_lifetime( $interval, $url ) {
	if ( 'https://mysite.org/feed' == $url ) {
		$interval = 3600;
	}

	return $interval;
}
add_filter( 'wp_feed_cache_transient_lifetime', 'danniee001_feed_lifetime', 10, 2 );

Add it to a child theme’s functions.php file, or a simple plugin.

That example changes the expiration for https://mysite.org/feed to 3600 seconds, or 1 hour. Change the URL to the URL to your feed and 3600 to the expiration time you want. But don’t go too low or you could negatively affect your site’s performance.

Hi Jacob!

I did exactly what you suggested and created my very first child theme! So today I learned two things, how to create a child theme and how to change the time interval for rss!

Thank you so much

Kind regards