Why Are Android Notifications Confused?

Question

Java

Hello
Please help me understand why notifications behave strangely.
I will describe: a notification comes from the group, but when you click on it, the wrong (other) group opens (ProfileActivity in the code).
Here is a link to the current code: https://pastebin.com/LuccdJnY
The correct data is leaving my server on FCM, there is no error here.
At first I thought that they were somehow mixed up in places, but also not, sometimes it opens correctly, and sometimes, just like that, it opens unexpected groups at all ......
I even replaced the notification ID generation with one that would definitely be unique but didn't help:

tag = String.valueOf(System.currentTimeMillis());
notificationManager.notify(tag, 0, notificationBuilder.build());

Please help!

This code is most likely error-free:

Intent intent = new Intent(this, ProfileActivity.class);
intent.putExtra(ProfileActivity.USER_ID_EXTRA_KEY, uId);

She's probably here somewhere.

intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_ONE_SHOT)

I don't know