Moved APs to Central - Cannot send/receive email via iOS Mail App

Hi All,

Weird issue. I moved our Sophos Access Points from the XG firewall to Central for management. I created SSID in Central and enabled NAT for the network and gave it 8.8.8.8 as DNS.

When iPhones now connect to that AP in Central, they can no longer retrieve email from Exchange server via the Mail app on iOS. They can retrieve mail if using the Outlook app.

When using the Mail app, an error appears about the mail server being untrusted. When tapping on details, it shows a Sophos Appliance Certificate as being the culprit. I checked the certificate on the XG, and it doesnt expire for another 10+ years.

Any suggestions for a resolution?