Each monitor rail has its Vout Exponent, which limits the maximum voltage the device shall return. Make sure that the Vout Exponent is set to a proper value for the application. When the "Set for Me" box is checked, the GUI sets the Vout Exponent automatically based on the your inputs.
For more FAQ please check the following document.
UCD90xxx Family Frequently Asked Questions and Answers
UCD9090 UCD9090A UCD90120 UCD90120A UCD90124 UCD90124A UCD90160 UCD90160A UCD90240 UCD90320 UCD90320U