I have noticed similar behavior in Experience Builder, but there is a solution for it (https://community.esri.com/t5/arcgis-experience-builder-questions/search-requires-selection-twice-an...). I am running into a similar issue in a Survey123 Web Form.
In the app, I can tap one of the search suggestions and it populates the Address question. However, when the survey is accessed through the web form, the suggestion has to be selected, then after clicking on the search bar again, the suggestion is tapped again (video snippet attached).
Is this expected behavior? I thought it might have to do with there being 2 locators in our organization, but I cannot limit the survey to only use one.
An update on this:
Tech Support has identified this as BUG-000174706. The current status of the bug is "Under Consideration". The "workaround" is to access the survey using the Survey123 field app. However, the use case in which the original issue occurred is in a public facing survey for a local government. So, it's unrealistic to expect every citizen to download the Survey123 app.