Is the symbology applied to one of the views but not the other or original? Go to the item folder in ArcGIS Online and look at the data on the Visualization page. Take a look at the stakeholder view the same way, and then in any web maps you have added it to.
A Hosted Feature Layer will have default symbology (item details > visualisation tab).
A Hosted Feature Layer View (used to share access for fieldwork or stakeholders) can have the symbology modified independently to other views and the parent hosted feature layer.
A Web Map layer configuration can also modify the layer symbology; you can save the symbology back to the default for the layer(or view) in the map contents layer options.
Another consideration could be that the symbology that has been applied may not be supported in Survey123 and has been downgraded
Or another is that the map used for data collection is connected to a different map, or is not online.
Please let us know if any of the above may apply. If further assistance or investigation is required - please include additional details such as how it was set up, what version / environment, and what changes were made after the survey was published.
Cheers
