Remove the second tiled map service layer from the web map or replace it as the basemap and the issue does not reproduce. Alternatively, use an iOS device on a previous version of the OS or an Android device.
Finally, create a custom basemap to alter the web map JSON so that Collector for ArcGIS perceive it as a single basemap layer. Use the following steps:
1. Navigate to: http://pholleran.github.io/agoAdminTools
2. Sign into the application using ArcGIS Online credentials
3. Navigate to the Tasks drop-down > Create Custom Basemap.
4. Set the Esri topographic map as the basemap layer:
http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer
5. Set the tiled map service as the overlay layer
6. Give the map a tile. Return to ArcGIS Online and a new web map is created in the content.
7. Open that web map and add the feature service. Save the changes.