Users are not entering series on login or page refresh. Have to wait for 1 hour cycle.

I have a series where users are not matching after they login or when they refresh the page after login. Users are getting added only after the hourly sync runs to add new users to the series.

What could be going wrong here?

[Updated]: Sharing more context here - Users are only entering the series when the hourly check happens. This is a problem for me because the First Run Experience of the app is part of the Series.

My series entry rule has two conditions - email should contain a particular domain and a custom attribute should be true. The custom attribute is updated async from the app through intercom(update) call. However, when the call is coming through the user is getting updated with the right value of the attribute (checked in user list) but the user is not entering the series till the next hourly sync happens.