Seems to be a mistake in the KML being generated by the grid service. It's outputting a <Description> tag in folder
<Folder>
<name>Grid (level 2)</name>
<Description></Description>
But its <description> in KML. KML is case sensitive. In general KML uses convention of using capital for tags that (may) contain other other KML tags, ones that contain only values, use lowercase.
The placemarks have the correct case
<Placemark>
<name>846XPP00+</name>
<description>
<b><...
I think the web version of Google Earth will silently ignore invalid KML.
The Pro version can be configured (Tools > Options > General -> KML Error Handling) - so could ignore the error, and continue to use it. Dont know if the grid service ever actully tries to put a description. In my test the <Description> is blank anyway.
The grid service page says to report bugs at
but seems to slightly in in limbo as the KML code isnt part of
so dont know if the KML stuff is technically open source.