Loopback - getting function back instead of values

For some endpoints I get a function back when called instead of the actual values (code at the end). It looks like that it only appears for nested endpoints through my Patient model. E.g. localhost:3000/api/Patients/{id}/MeasDescPatRels However this works fine: localhost:3000/api/Patients/{id}/MeasuredDataPoints In my webapp it is not really a problem, apparently the returned function is just called by JS and gives me the correct data. However I have an android app calling the exact same endpoints.

Returned function:

"function (condOrRefresh, options, cb) {\n        if (arguments.length === 0) {\n          if (typeof f.value === 'function') {\n            return f.value(self);\n          } else if (self.__cachedRelations) {\n            return self.__cachedRelations[name];\n          }\n        } else {\n          if (typeof condOrRefresh === 'function' &&\n              options === undefined && cb === undefined) {\n            // customer.orders(cb)\n            cb = condOrRefresh;\n            options = {};\n            condOrRefresh = undefined;\n          } else if (typeof options === 'function' && cb === undefined) {\n            // customer.orders(condOrRefresh, cb);\n            cb = options;\n            options = {};\n          }\n          options = options || {};\n          // Check if there is a through model\n          // see https://github.com/strongloop/loopback/issues/1076\n          if (f._scope.collect &&\n            condOrRefresh !== null && typeof condOrRefresh === 'object') {\n            //extract the paging filters to the through model\n            ['limit', 'offset', 'skip', 'order'].forEach(function(pagerFilter) {\n              if (typeof(condOrRefresh[pagerFilter]) !== 'undefined') {\n                f._scope[pagerFilter] = condOrRefresh[pagerFilter];\n                delete condOrRefresh[pagerFilter];\n              }\n            });\n            // Adjust the include so that the condition will be applied to\n            // the target model\n            f._scope.include = {\n              relation: f._scope.collect,\n              scope: condOrRefresh,\n            };\n            condOrRefresh = {};\n          }\n          return definition.related(self, f._scope, condOrRefresh, options, cb);\n        }\n      }"

MeasDescPatRels model (not working):

{
    "name": "MeasDescPatRel",
    "base": "PersistedModel",
    "strict": false,
    "idInjection": false,
    "options": {
      "validateUpsert": true
    },
    "properties": {
      "reminderData": {
        "type": "object"
      },
      "alarmData": {
        "type": "object"
      }
    },
    "validations": [],
    "relations": {
      "patient": {
        "type": "belongsTo",
        "model": "Patient",
        "foreignKey": "patientId"
      },
      "measurementDescription": {
        "type": "belongsTo",
        "model": "MeasurementDescription",
        "foreignKey": ""
      }
    },
    "acls": [
      {
        "accessType": "*",
        "principalType": "ROLE",
        "principalId": "$everyone",
        "permission": "ALLOW"
      },
      {
        "accessType": "WRITE",
        "principalType": "ROLE",
        "principalId": "$everyone",
        "permission": "ALLOW"
      }
    ],
    "methods": {}
  }

HomeGateway model (not working):

{
  "name": "HomeGateWay",
  "base": "PersistedModel",
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    "model": {
      "type": "string",
      "required": true
    },
    "version": {
      "type": "string",
      "required": true
    },
    "onlineStatus": {
      "type": "boolean",
      "required": true
    },
    "macAdress": {
      "type": "string",
      "id": true,
      "required": true
    }
  },
  "validations": [],
  "relations": {
    "patient": {
      "type": "belongsTo",
      "model": "Patient",
      "foreignKey": ""
    }
  },
  "acls": [
    {
      "accessType": "*",
      "principalType": "ROLE",
      "principalId": "$everyone",
      "permission": "ALLOW"
    }
  ],
  "methods": {}
}

MeasuredDataPoint model (working):

    {
  "name": "MeasuredDataPoint",
  "base": "PersistedModel",
  "strict": false,
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    "created": {
      "type": "date",
      "required": false
    },
    "timestamp": {
      "type": "date",
      "required": false
    },
    "lastUpdated": {
      "type": "date",
      "required": false
    }
  },
  "validations": [],
  "relations": {
    "measurementDescription": {
      "type": "belongsTo",
      "model": "MeasurementDescription",
      "foreignKey": ""
    },
    "patient": {
      "type": "belongsTo",
      "model": "Patient",
      "foreignKey": "patientId"
    }
  },
  "acls": [
    {
      "accessType": "*",
      "principalType": "ROLE",
      "principalId": "$everyone",
      "permission": "ALLOW"
    }
  ],
  "methods": {}
}

via Shrimbo