There could be multiple reasons for it:
- Make sure the exact targeting rules defined in WebEngage have also been applied to GA.
- For user type targeting parameter, there could be little variation in the tagging a user as repeat or a new. It depends on session length as well as timing of the respective code integration.
- For geo-based targeting, the geo location is found out based on IP and it may vary.
- Notification once closed, clicked or exceeds its maximum view limit per visitor is not shown to the same visitor. However, GA will keep aggregating page views for the same visitor.