webRTC的兼容性

我用几个不同的设备测试了一下，发现pc的360浏览器（内核78）、chrome浏览器（内核84）
以及安卓手机 android8.1(chrome内核58)都没有问题，
但是用了一个android7.0（chrome内核51）有问题，别的设备看不到他的视频和音频，但是他可以看到别人的视频和音频。
请问是什么原因？怎么解决呢

No source file, test, or entry point is named. Start by reproducing the one-way media problem on Android 7.0 with Chrome 51 and compare it with the listed working browsers; done means identifying the compatibility cause and verifying that both video and audio are visible to other participants.

Written by the indexing model from the issue text.