Annoying PHP error on Meta Box Version 1.13.2

Hi,
I'm really enjoying using Meta Box, good work!

I have an annoying php error which I thought I'd better run past you - I'm sure its nothing serious but keeps popping up in Query Monitor:

wp-content/plugins/meta-box-aio/vendor/meta-box/meta-box-builder/src/Register.php:32
MBB\Register->register_meta_box()
wp-includes/class-wp-hook.php:287
apply_filters('rwmb_meta_boxes')
wp-content/plugins/meta-box/inc/core.php:49
RWMB_Core->register_meta_boxes()
wp-includes/class-wp-hook.php:287
do_action('init')
wp-settings.php:557

Cheers, M