Automatic theme and plugin update filters not working in WordPress 5.1.1

[emergencyscotch]

Hello, for some reason automatic theme and plugin updates don't appear to be working using the instructions from the Codex:

​https://codex.wordpress.org/Configuring_Automatic_Background_Updates

I created a must use plugin per the Codex instructions and verified the plugin is present and activated:

<?php
add_filter( 'auto_update_plugin', '__return_true' );
add_filter( 'auto_update_theme', '__return_true' );

I ensured that automatic updates are *not* disabled in wp-config.php

I also tried adding the filters directly to the theme's functions.php with no luck.

I have tried manually kicking off the update checker and waiting over night, but still no plugins or themes are updated.

I enabled debug + logging in wp-config to try and see what was happening, but I'm not getting any output

If this is not a bug, but a problem on my end, I would appreciate any help on how to further troubleshoot the issue.

Thank you,