Emails in Public folders aren't showing up in Outlook

[Barry Ralphs]

Hi,
I've inherited our Devocot setup from someone else & don't know much 
about it.
I can view our Public email folders fine in Thunderbird, but when I try 
it with Outlook 2013, I can see the folder structure fine, but when I 
click on a folder it doesn't show any emails.
Here's a screen shot of Outlook: https://imgur.com/CHIDJOr
And Thunderbird: https://imgur.com/WxmsUTM

Here's the version info & config output:
# 2.2.36 (1f10bfa63): /etc/dovecot/dovecot.conf
# OS: Linux 3.10.0-1062.1.1.el7.x86_64 x86_64 CentOS Linux release 
7.7.1908 (Core) ext4
# Hostname: nikola
auth_mechanisms = plain login
auth_verbose = yes
debug_log_path = syslog
disable_plaintext_auth = no
info_log_path = syslog
mail_location = maildir:/home/%n/Maildir
mbox_write_locks = fcntl
namespace TMpublic {
   location = maildir:/iscsi/public/Maildir:INDEX=~/Maildir/public/index
   prefix = Public/
   separator = /
   subscriptions = no
   type = public
}
namespace inbox {
   inbox = yes
   location =
   mailbox Drafts {
     special_use = \Drafts
   }
   mailbox Sent {
     special_use = \Sent
   }
   mailbox Trash {
     special_use = \Trash
   }
   prefix =
   separator = /
   type = private
}
passdb {
   driver = pam
}
ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
ssl_key =  # hidden, use -P to show it
userdb {
   driver = passwd
}

Any suggestions on how to get the Public folders to show the emails in 
Outlook?
Thanks for the help.