What is the instability of ios 15 network?

This may be because the signal is weak, so I didn't search for this signal. The solution is as follows:

Tools/raw materials

iphone 12

ios 15.0

1, open the mobile phone control center.

2. Click the flight mode.

3. Open the flight mode and click Close.

4, so that the mobile phone will have a signal.

IOS 15 upgrades FaceTime video calling to bring spatial audio technology. With the help of multiple microphones and internal audio processing algorithm, video call has real sound field effect.

FaceTime also supports "speech enhancement mode", which shields background noise through algorithms and can obtain clear speech in noisy environment; The new version of FaceTime also supports automatic beauty in videos, and can also achieve good results in multiplayer videos.