Thank you for your post! I understand that we were able to resolve your case over email but I will post a solution here in the event that anyone else has the same question.
On Android devices, please ensure that the layer you have linked to your map is set as the “Current Layer” if you are wanting to add new features to said layer. You can specify this on the Edit Layer page by long pressing the layer and tapping the pencil (Edit) icon at the top.
For either device, please ensure that visibility is toggled on in order to see your layer on the map. Sometimes visibility can be turned off accidentally which will hide all map features contained in the layer. To enable visibility on iOS, simply open the Map Features window from the Map view and tap the layer icon to the left to toggle visibility on/off. On Android, long press on the layer and tap the eye icon at the top to toggle visibility.
Please let me know if there are any further questions!
All the best,
Avenza Systems Inc.