MapRoulette OSC doesn't always change the OSM layer

[taylor.smock]

API calls that MR makes (copied from JOSM console log, http://localhost:8111 added):

​http://localhost:8111/load_and_zoom?left=175.1235616207123&right=175.13642549514773&top=-37.26303869648842&bottom=-37.27009132988014&new_layer=false&layer_name=MR%20Task%2098697933%20Changes&changeset_comment=%23maproulette%3A%20New%20Zealand%20-%20WaterWayCheck&changeset_source=&select=w439812515

​http://localhost:8111/import?new_layer=false&layer_name=MR%20Task%2098697933%20Changes&layer_locked=false&download_policy=&upload_policy=&url=https://maproulette.org/api/v2/task/98697933/cooperative/change/task_98697933_change.osc

Original MR task: ​https://maproulette.org/challenge/18886/task/98697933

task_98697933_change.osc

<?xml version="1.0" encoding="UTF-8"?>
<osmChange generator="atlas ChangeDescription v0.0.1" version="0.6">
  <modify>
    <way id="439812515" version="1" visible="true">
      <tag k="LINZ:source_version" v="2012-06-06"/>
      <tag k="LINZ:layer" v="drain_cl"/>
      <tag k="waterway" v="drain"/>
      <tag k="attribution" v="http://wiki.osm.org/wiki/Attribution#LINZ"/>
      <tag k="source_ref" v="http://www.linz.govt.nz/topography/topo-maps/"/>
      <tag k="LINZ:dataset" v="mainland"/>
      <nd ref="3064243489"/>
      <nd ref="3064243448"/>
      <nd ref="3064243419"/>
      <nd ref="3064243388"/>
      <nd ref="4374879708"/>
      <nd ref="4374879645"/>
    </way>
  </modify>
</osmChange>