This behaviour is caused by the questions available within the Onboarding Wizard. If you have follow-up questions that only become visible based on the answer to a conditional question, please ensure that these are optional to answer.
For example, "If you are currently studying a qualification, please confirm below which organisation you are studying with and who is funding the qualification?”
The follow-up question(s) only appear if the question above is answered “Yes”, so can't be mandatory in all situations. These questions can be amended in the Onboarding Wizard section of the Programme Builder, as seen below: