Sql error in wp_bp_notifications query

Hi,

Reviewing the server error logs, we found that this query produced an error:
SELECT MAX(id) FROM wp_bp_notifications WHERE user_id = 0 AND component_name IN ('xprofile','friends','messages','activity','groups','members','buddypress_member_review','notification-buddypress') AND is_new = 1;

We find that in the wp_bp_notifications table, there are more than 784526 results for user_id=0

SELECT * FROM wp_bp_notifications WHERE user_id = 0 ORDER BY wp_bp_notifications.date_notified DESC

We don’t have a user with user_id=0

Is this an error? Why are records saved in this table for the user user_id=0?

Can we optimize this somehow?

Can we delete those records?

Thank you!

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