Hey guys, I resolved my issue, and hope that it helps you. I was wrong to add a filter to wp-config.php because filters are supposed to be added to a plugin. I also assumed the updates would happen immediately, but WordPress checks every 12 hours. Also, the "Updater" plugin successfully updated my plugins after an hour.
I'm using the "Automatic Plugin Updates" plugin and I'm expecting it will work after waiting 12 hours for WordPress to check for updates.
I also wanted to automatically update WordPress core files (major and minor, but not dev), so I created a plugin for that. Here's how:
1. Create a folder on your computer called "automatic-wordpress-updates"
2. Inside that folder, create a file called "automatic-wordpress-updates.php"
3. Add this code to the file
Plugin Name: Automatic WordPress Updates
Description: Enable major and minor core updates. Disable dev updates.
add_filter( 'allow_minor_auto_core_updates', '__return_true' );
add_filter( 'allow_major_auto_core_updates', '__return_true' );
add_filter( 'allow_dev_auto_core_updates', '__return_false' );
4. Save it and upload the folder to your plugins directory.
5. Activate the plugin, and you should be all set.
I'm still waiting to see if all these updates will get made after 12 hours. If you see something wrong with my code, let me know.