Blank attribute values in a KML, despite valid display field

[RandyMcGregor_BMcD]

The layer from which this KML was made has a valid display field set. I've actually tried a couple of different ones and the resulting KML is not recognizing them. I've made a lot of KMLs and if a display field is set, you see the values of that field in the output. Is this a bug in 3.6 (just updated), or is there something I'm missing?

Thank you,

[Robert_LeClair]

I did find BUG-000152058 where a similar behavior shows when enabled labels are defined by an expression.  Do you have any Arcade, Python, VBScript and/or JScript expressions defined?  If so, remove those and apply your workflow again.  What is the result?