I'm experiencing some issue related to the subscription process from mobile app.
In particular, I can see the link between visitorID and profile but the registration token seems to be empty.
The demdex call contains the device token, so the implementation seems to be correct:
I noticed more than one post related to this issue, but I can't find the solution.
Please raise a ticket to the support portal using the instance URL.
This seems to be a known issue in some ACS instances where the pipeline topics are mis-configured in the server configuration or missing the real-time topic for pipeline.
Generally if you select subscription in the nav tree of charles you would get a 500 error code.