WIFI troubles following new Mac OS X Big Sur installation

The issue occurs on two differents MacBook Pro (15-inch, 2018) after Big Sur installation (I did not have any issues with Catalina)

The Wifi connexion work fine for a long time (1 or 2 hours) and crashed suddenly

I need to restart the Mac to retrieve my WIFI connexion

I tried

To Stop and Restart my WIFI connexion: no effect

To reset the T2 chips : no effect

To renew the IP address : no effect

Each time only a reboot is efficient