If you are using PAN-OS 10.x.x or 11.0.x and the
Use Default
Browser for SAML Authentication option is selected in any of
the portal agent configurations, the
Use Default
Browser option on the Client Authentication window will be
automatically enabled after you upgrade to PAN-OS 11.1.0 or later. Starting
from PAN-OS 11.1.0, the default browser behavior is controlled by the client
authentication setting. For more information about this feature and upgrade
considerations, see
Manage Browser Selection for SAML
Authentication.