Comment 3 for bug 1848919

Indeed I can see the rules you mention in /etc/apparmor.d/abstractions/base, which is included by /var/lib/snapd/apparmor/profiles/snap.chromium.chromium.

However I can reliably reproduce the issue, and I'm seeing the following denial:

  AVC apparmor="DENIED" operation="open" profile="snap.chromium.chromium" name="/home/ubuntu/.Private/" pid=11167 comm="pool" requested_mask="r" denied_mask="r" fsuid=1000 ouid=1000