After upgrading to SEP 14.3 RU6 and enabling Web and Cloud Access you will expect to see the SAML authentication challenge-response for your identity provider only. In some cases you may see an additional pop up:
VPN is trying to modify your system settings. Enter your password to allow this.
SEP 14.3 RU6
Mac client
Web and Cloud Access
SAML
The Symantec development team have investigated this and reported their findings to Apple as a macOS defect. It has only been seen on Ventura versions 13.x.
This challenge-response pop up can be completed normally, or dismissed, and in both circumstances Symantec software will continue to work regardless of how the popup is handled.