Labels do not honor the web map settings in Collector for ArcGIS (Windows).

Solução Provisória

Since Collector for ArcGIS (Windows) pulls labeling information from the REST endpoint instead of the web map, publish a new hosted feature layer to Portal for ArcGIS or ArcGIS Online and set label properties at the time of publishing in the MXD/APRX. Then, take the web map in Collector for ArcGIS (Windows) and see the labels are displayed as in the desktop client.

Etapas para Reproduzir