after_save_post on settings page - values not updated

Hello,

Obviously, the settings page isn't a post, so the function update_post_meta() doesn't work to update the settings page. You can use the function rwmb_set_meta() or update_option() to update fields on a settings page.

Please follow the documentation
https://docs.metabox.io/functions/rwmb-set-meta/
https://developer.wordpress.org/reference/functions/update_option/
https://docs.metabox.io/extensions/mb-settings-page/

Hello,

It isn't an issue with the action hook rwmb_after_save_post. The issue lies in the function update_post_meta() in the callback that you are using. The settings page doesn't have an object ID, so apparently, the function update_post_meta() won't work to update a post meta for a post.

Is the documentation incorrect?

The documentation is correct. But the function update_post_meta() will update the post meta, not the settings page value. Here is an example:

add_action( 'rwmb_fundraiser-fields_after_save_post', function( $object_id ) {
    update_option(...);
} );

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