It might depend on a few things -
What type of device are you using to collect the data?
Are you using an external GPS?
Have you applied the setting within the body::esri:style for the method of capture (method=vertex for GPS enabled capture)?
How is your form setup; do you have multiple questions for multiple features? I have noticed that if you build a form with two types of geometries within the main form; that the second will not work unless it is placed into a repeat. This is due to the underlying structure of how Survey123 works with a Hosted Feature service and requiring a primary feature layer to write the data into.
I have a survey form that uses a geoshape as the main feature, but then also have related 2 separate points (one for photos and another for tabular data), a separate polygon, and two related tables for each polygon captured. works great.