Bug in Activate Smart Campaign API

When calling the REST API I am finding some campaigns that fail to activate via the API although they activate fine when don manually.  (Using this REST API  https://developers.marketo.com/rest-api/assets/smart-campaigns/#activate )

The error returned by the API is:

{'message': u'Wrong number of operands for the given operand', 'code': u'709'}

By trial and error, I determined the issue in Marketo is a "Campaign is Requested" trigger that has a source value of  "is any"

If that is changed to a specific value such as "is Marketo Flow Action" then the campaign activates just fine via the API.    So this is clearly a case of acivation thru the API doing validation differently (incorreclty( than with activating manually through the GUI.

This is simple to reproduce:  just set up a campaign with "Campaign is Requested" trigger that has a source value of  "is any" as in screen shot and then try to activate through the API.