Because iPhone doesn't allow closing of notifications by the service-worker, notifications can not use different tags per notification, but must rather use the user ID as tag:
user_<USER_ID>
Notes
notification data has previously been serialized and included in the tag. Instead, a new way of passing data with the notification must be used.
anisus
commented
2 months ago
Issue
Because iPhone doesn't allow closing of notifications by the service-worker, notifications can not use different tags per notification, but must rather use the user ID as tag:
user_<USER_ID>Notes