Hi Bill,
I followed the LinuxBabe tutorial to setup passbolt with postgresql on Ubuntu 22.04 and I got the same issue than you, no avatar:
By inspecting the browser logging console, I can see the avatar got 404 not found.
If you followed the same tutorial than me, you have this section in your /etc/nginx/conf.d/passbolt.conf:
# A long browser cache lifetime can speed up repeat visits to your page
location ~* \.(jpg|jpeg|gif|png|webp|svg|woff|woff2|ttf|css|js|ico|xml)$ {
access_log off;
log_not_found off;
expires 360d;
}
Remove this section from your nginx configuration file, then restart nginx:
sudo systemctl restart nginx
You should see your avatar now \0/
Let me know if it works for you 
Cheers,