Do not use reserved words as field names in Survey123. The Survey123 desktop app automatically creates feature layers in ArcGIS Online with the field "rowid". This wasn't a problem until we tried to import the data from arcgis online into ArcSDE. BOOM, NOPE. "rowid" is a reserved word in Oracle. We worked around the issue by first copying the data to a file geodatabase then appending the data to ArcSDE and mapping the data to a non-reserved word field name "row_id". This workaround creates more room for error and slows the import process.
Survey123 should use field names that respect the reserved word restrictions of Oracle. The same should be true of all ArcSDE supported databases.