We have a app with 3 different flavours. We set them up to use firebase notifications with one project per flavour. So 3 apps from the same codebase each one with there own firebase project.
We also added a custom event that we enabled for conversion.
For one of the apps, when sending pushes I can select the custom event to be used as a conversion event with the push, and that works and tracks fine. For the other two I can select the custom event fine but when I try to send the notification I get a error:
"Unable to reserve a user property for Notification conversion funnel analysis for"
Anyone know why this occurs and how to resolve it?
I fixed it by adding a user property to the user properties tab in the analytics section of firebase console. The user property had nothing to do with the actual conversion event but adding at least one user property seems to have initialised something that made the conversion event selectable.