Network connexion instable since last update

I came back from hollidays on tuesday and accepted the update proposed.
I have now Parallels pro Edition Version 19.1.1 (54734).
But since, when working on windows, I am disconnected from internet very often. If I stay on one same app, it's ok (like a teams meeting) but if I move from one connected app (like teams) to another (like outlook to send an email or chrome to lauch a new tab), then I loose internet.
The only way I have to restore it, is to go in the top bar and change the source set-up. If it's shared network, I change to bridge/Wifi, and the other way around for the next disconnection.
If I am in windows and go on the mac, then the connection in windows cuts quasi-each time.

I can't find what tringers it, but this is painful. I can't multi task; when in a Teams meeting I can't consult my notes or my mails...
I haven't changed anything in the set-up since it's been working perfectly from the beginning and I'm not qualified for that...
I need your help please.