Editbox caption disappears when datatype not set to string

[RogerAsbury]

I am working on a plugin to ArcGIS Pro using the ArcGIS Pro SDK. In working on the config.daml, I have created two edit boxes. One is using a datatype of int64 and the other of type string. Below is their entry under the controls portion of the script:

<editBox id="Extension_SearchPANBox" caption="PAN" className="SearchPANBox" dataType="int64" sizeString="AAAAAAAAAAAAAAA" >
    <tooltip heading="Tooltip">Enter PAN to search, then hit Enter.</tooltip>
</editBox>
<editBox id="Extension_SearchTownRangeBox" caption="TRS" className="SearchTownRangeBox" dataType="string" sizeString="AAAAAAAAAAAAAAA">
    <tooltip heading="Tooltip">Enter Township and Range to search, then hit Enter.</tooltip>
</editBox>

When I run the app, I would expect to see two search boxes, one captioned PAN and the other TRS. However, when run, the caption for PAN does not show up, as shown below.

 

A quick test of the three dataTypes available (int64, double, string) suggests the caption only shows up if the datatype for the field is a string. I don't see anything in the class description (https://pro.arcgis.com/en/pro-app/latest/sdk/api-reference/index.html#topic10453.html) that would suggest this is expected behavior.

Is this a bug, or is there something specific I'm missing?