Inconsistency in usage of fit labels between GCM and web

I have this fit field:

    <fitField id="0"
      displayInChart="true"
      displayInActivityLaps="false"
      displayInActivitySummary="false"
      sortOrder="0"
      precision="0"
      chartTitle="@Strings.fitCurrentHeartRateChartTitle"
      dataLabel="@Strings.fitCurrentHeartRateDataLabel"
      unitLabel="@Strings.fitBpm"
      fillColor="#f25b0a" />

with these strings:

    <string id="fitCurrentHeartRateChartTitle">ANT Heart Rate (bpm)</string>
    <string id="fitCurrentHeartRateDataLabel">ANT Heart Rate</string>

And while I was trying to figure out which of the 2 labels is displayed where (I only see chartTitle, I have no idea why there is a dataLabel and why that is required if it's not used at all, but that's another story (or is it?)) I noticed that while in the built-in fields, i.e: Heart rate there are 2 ways it is displayed:

On the web it's "Heart rate":

While on GCM it's "Heart Rate (bpm)":

However in the CIQ field I only see "ANT Heart Rate (bpm)" (the chartTitle) everywhere.

So I'm not sure what is the bug, or what behaviour is the intended, what I see in the built-in fields or in the CIQ, but I have a feeling that the difference I see in the built-in fields is supposed to be also in the CIQ field, and there it is where the dataLabel is supposed to be used.