The output volume is abnormal when VPIO is switched to RemoteIO

The voice call in our game has such a usage scenario: when the player does not wear the headset or Bluetooth, we use the VPIO mode to turn on the microphone. On the contrary, the player wears the headset or Bluetooth, and the remoteIO mode is used to turn on the microphone. So we have a switch between VPIO and RemoteIO。When we only use RemoteIO (the player has been wearing headphones or Bluetooth since the game), the output volume does not change before and after the microphone is switched on. When we only use the VPIO mode (the player has not been wearing headphones or Bluetooth since the game), before and after turning on the microphone, the output volume will reduce a little (because turning on the microphone will cause the phone to enter the VPIO and the echo cancellation will be turned on), the performance of the output volume in the above two scenarios is normal。However, when we switched between VPIO and RemotoIO (the player didn’t wear headphones or Bluetooth at the beginning, and brought headphones or Bluetooth in the middle of the game), we encountered some problems: As long as I have used VPIO mode before RemotoIO mode, the output volume in RemoteIO mode after turning on the microphone will be the same as in VPIO mode (normally the output volume in RemoteIO should be greater than in VPIO mode), turn off the microphone ,The output volume will become normal.What confuses me is: My understanding is that when we use RemoteIO, the mobile phone should not do some suppression-like speech algorithms, so when we only use RemoteIO, the output volume of the mobile phone does not change. When we use VPIO, the mobile phone will use echo Algorithms, and perhaps dynamic compression and some gain algorithm processing. At this time, the output volume will be reduced to better handle the echo. This behavior is normal. However, when I switch between VPIO and RemotIO, I feel that when I use RemoteIO (VPIO resources are released), some of the previous VPIO algorithm processing is still reserved (may be dynamic compression or gain algorithm), which finally leads to the output volume under RemoteIO is the same as that under VPIO, and this only happens on all of IOS14, the previous version is normal (anytime you enter the remoteIO mode, the volume does not change). I want to know, For IOS14 this behavior (VPIO and RemoteIO switching causes the volume of RemoteIO to decrease) is normal? If it is not normal, how can we solve it?