K8y
You might need your carrier's voicemail app.
Only once did I receive a notification from private space late.
Does whatsapp normally notify you on time or always late?
Are you on a connection that has a good internet connection? Using a vpn could be causing many of your issues.
If you're using private space, after unlocking PS with a pin code, try opening the apps that you'd like to receive notifications from. Might help.