播放界面跳转界面返回后继续播放只有声音，界面卡主

播放界面跳转到另一个界面，然后返回。视频播放后只有声音，界面卡在跳转那帧。

The issue identifies a playback failure after navigating away from and returning to the video screen, but names no source file, test, or platform-specific entry point. Start by reproducing the navigation and playback sequence on Android and iOS, then trace the affected playback and screen lifecycle paths. Done means the video continues rendering after returning, rather than showing only audio and a frozen frame.

Written by the indexing model from the issue text.