1. barrage setting: users can select the number of displayed barrage in the barrage setting. If it is set to display only a few, then even if there are 100 barrage settings, only the number of settings will be displayed.
2. barrage review: the content of barrage will be reviewed. If the content of the barrage violates community norms or laws and regulations, the barrage will be deleted or hidden, resulting in a decrease in the number of actually displayed barrage.
3. Network problem: If the user's network conditions are not good, it may lead to incomplete loading or incorrect display of the barrage.