I have been having this intermittent problem of the mbox call only returning the sessionId in the network tab instead of the tests associated with the URL. My getOffers call is correct and I have tests live that should be delivered to the page.
Sometimes I have this issue when I am implementing at.js other times it just starts happening when after at.js has been working and delivering tests. Does anyone know what this is an indicator of?
As you probably realized when you only get a sessionid back in your response it means that.
This is not a first time visitor/session call (otherwise the tntId would also be present),
That request did not qualify for a live activity in Target (otherwise an offers object would be present).
When you have intermittent problems for qualifying I would first double check all the entry and audience conditions of the activity. Is this a visual composed activity or a form based? With visual composed activities, sometimes the entry conditions can be the issue. Protocol, subdomains, paths, query parameters all matter for activity entry unless you've explicitly added an OR template rule to ignore them.
On the overview tab what does the activity location show?
In this case it doesn't matter if I load https://sb.com/your-trip/index-1.html or http://www.sb.com/your-trip/index-1.html but without the OR condition neither of those URLs would properly enter.