I face the same issue when sending notifications to Android real device. Would be great if you share the solution you have found since the time you made your post.
Some points regarding your issue:

• The expo docs say that push notifications only work on real devices: https://docs.expo.dev/versions/latest/sdk/notifications/#usage.

• setNotificationHandler makes effect only when the app is foreground: https://docs.expo.dev/push-notifications/what-you-need-to-know/#push-notification-behaviors