Piano teacher cannot hear students playing notes sound cutting in out

Teaching Piano online with zoom For the last 2 years has been excellent until now... 

Problem 

When students play piano during lesson for my mother who teaches online, audio at a certain threshold cuts out on her side / filtered. softer played notes from what I noticed so far this is a new problem so I'm all over it and monitoring. 

The problem began last week so I believe ( not 💯) it is an update that has been rolled out across Zoom community on Dec 29,2022

I am currently changing experimenting on my side

windows driver sound render raw

Original sound for musicians off ( 

Our machine is a Windows 11 machine  I have not applied any driver or Windows updates recently.

I have a Nvidia card that has not been modified or updated nothing has been changed on local machine. Also use an external webcam that is not been updated or settings changed

Students have a diverse range of devices from ipdads to iphones, Android, chrome books to windows laptops (best sounding so far) with external and internal camera/mic

Nothing was changed on our side before this problem came about I don't like to change anything on their side because most piano students are using their parents' device, and most parents are prominent CEOs celebs Etc that use their devices in meetings ( I'm an IT guy and I know for sure their it guys wouldn't be very happy campers if they picked up someone was in there changing things) and certainly don't want to mess with Apple devices. 

anyone have any ideas, or info and could share that'd be awesome happy New Year everyone! matt