Registration Question Options

Frustration overload having recently upgraded to Pro plan. Trying to add one question to the registration form and only two options are provided for "Question Type" - Single Choice or Short Text. Since this requires someone to actually answer - e.g. child's age, Short Text would seem to be the option, however the box below it highlights in blue yet I cannot type anything. Question 1 appears...I click on "Short Text"...I click on the box below and nothing. Can someone please help ASAP as this meeting is next week. Thanks.