Additional documents accepted by IRCC -- GCKey profile status changed from "waiting for document" to "we have received the documents". We didn't receive any other communication.
Pre-arrival letter was an email to PA's email address and also an additional letter in GCKey.
PPR is just an email in PA's email address.
Are you converting that text email to a PDF then? One of my cousin's grandma got her PPR in email text, but the webform wants a PDF submission...