Randomly be disconnected from my personal calls

For the past two weeks, my devices (Macbook Air M1) have been disconnected randomly during our calls and then reconnected after a few seconds which remove all the screen sharing.

It says poor internet connection but actually it's not since we checked carefully already.

- Internet: stable, strong signal, checked with the internet provider and also multiple apps.

- Devices: two different Macbooks - two different accounts - both are Pro users

Anyone knows the root cause and solution?