permanentID missing in IOS.conf

For some strange reason my permanentID changed to : “00000000-0000-0000-0000-000000000000”.
I think this is a part of the notification keys/IDs, because I don’t receive notifications any more.

Already tried to remove everything in the config files that is related to my iPhone.
Removed the HomeAssistant app from my iPhone, reinstalled en reconfigured everything.
But the permanentID remains “00000000-0000-0000-0000-000000000000”.

Where can i find this key?