LDAP authentication fails with error "user <username> not found" if using UPN to login Gateway

LDAP authentication fails if using UPN userPrincipalName to login Gateway. When running /tmp/aaad.debug log on NetScaler, the following error "user @domainname.com not found" is printed in logs. /usr/home/build/adc/usr.src/netscaler/aaad/ldapdrv.c528: receiveldapusersearchevent 0-2: ldapfirstentr...

Error: "Incorrect credentials. Try again." when logging into NetScaler Gateway

Users fail to log on to NetScaler Gateway with the following error: "Incorrect credentials. Try again." Log on through StoreFront is successful. From /tmp/aaad.debug, the following is the logon failure message: /usr/home/build/rs1011296/usr.src/usr.bin/nsaaad/../../netscaler/aaad/ldapcommon.c341:...