text: arcgis online - Collector App dropping collected points from one specific layer after submission? - Geographic Information Systems Stack Exchange
  I'm using the collector app for iOS (iPad Air 2) for water utility asset data collection. For every layer or asset type I can mark a point, fill out the form, attach photos, and submit. No problem. It immediately appears on the collector map and syncs with ArcGIS online. The problem is when I do this with valves and valves specifically, all of the above appears to work correctly, except the point on the map disappears after about 2 seconds. The valve attribute field is empty, none of the points, attachments, or associated fields are being saved. Everything else is perfect. Collector isn't throwing any errors and I cannot find out what's causing it to delete valve points. All of these layers are on the same feature service, created by ESRI. The valves layer has edit permissions and displays at the same scale as everything else.
  Is this a common bug? Am I doing something horribly wrong? I was working in an area with excellent cell service; I never went offline. Also, only points from this one layer were dropped; the hydrant points I collected right next to these valve points went through flawlessly. Even sitting here back in the office I can create little test points and the exact same thing happens: valves disappear, everything else saves.
  Maybe there is something wrong with your published feature service. Did you publish all the layers to a feature service from the same mxd? how did you create the webmap that collector is using? Did you add each feature service individually or did you add the whole feature server which contains all the layers? – PMK Mar 7 '17 at 19:19
  Try editing and adding points to the feature class from the mxd which you published from. Try republishing the feature service and recreating the webmap. How are permissions set up on that one feature class? I'm just grasping as straws here since I can't test it on my end. I have never had an issue like this but I think if you republished the service and the layers were in a different orders and the web map is still referencing the other ordered service that might cause issues but not the ones you're having. – PMK Mar 7 '17 at 19:19
  All the layers I've described thus far are published to a feature service from the same MXD, yes. After some experimentation I found that one specific field in the valves layer MUST be filled or else the same thing happens. Every other field can be empty. I do not know why; the domains of that particular layer are all set to accept null values. It's a work around, I suppose, but it's still baffling. I also attempted to delete that particular field in the map viewer, to no avail; it simply brings up the "delete" prompt, I click on it, and nothing happens. – Alastair Mar 8 '17 at 16:29
  There are two reasons that I can think of why points might disappear after being submitted.
  If there is a filter applied on the layer. If you add a point with attributes that get filtered out, then they will disappear due to the filter being used.
  If the way the points are being symbolised is filtering data out. For example, if the symbology is based on a field that is not being filled out, then the point might disappear as a result.
  In both cases, the data is successfully being submitted to the database, but you just can't see it! It would be worth looking at the raw data to see if the submissions are in fact being added!