Captive Portal with Microsoft 365 SSO Closes After MFA on iPhones

Hi everyone,

We’ve set up a captive portal for employees to connect their personal devices to our Wi-Fi using Microsoft 365 SAML SSO authentication.

When connecting from an iPhone, the captive portal opens correctly and redirects to the Microsoft login page. After signing in, users receive the MFA prompt to enter their code. However, when they switch to the Microsoft Authenticator app on the same phone to validate the MFA and then return to the Wi-Fi login screen, the captive portal closes automatically.

It seems that if you swipe up or switch to another app, the captive portal session ends, forcing users to start the process again. This creates an endless loop. Users authenticate successfully, but the portal resets before completing the connection.

Has anyone encountered this issue or found a workaround to keep the captive portal session active during

MFA on iPhones?

Thanks in advance!