Approval Notifications visible through BPM Worklist but not visible through Bell icon.

Summary:

When Employee Submits Personal Info update or change assignment request, we've configured approval in a way that it sends approval to users with particular role.

However, when we check approval notification from approver's user, it's not showing in Bell Icon but when we open worklist for same user, notifications are visible there.

Things which we've checked:

(Admin) Notification Mode in BPM Worklist: All

User Category Notification field is checked (Set to Yes).

Ran "Synchronize Notifications Global Header" scheduled process.

profile options values like BIP_ONLINE_NOTIFICATION_HCM and related profile options were changed to "true".

None of the above things resolved our issue. Please suggest if there can be any other things which can be checked/performed to resolve this.