For single or dual polarisation spectral line Science Goals, the user-defined calibration strategy that is suggested by the OT will cause an error in the time estimate. For unknown reasons, Single Continuum, Spectral scan and Full polarisation Science Goals are not affected.
A simple workaround is to simply add a second phase calibrator to the user-defined calibration setup. The time estimate will then work and the project will validate and can be submitted. Users that do not require the second phase calibrator should simply state this in their technical justification, and this will be taken into account during the Technical Assessment.