PC - DbD causes my computer to lose connection

Context : My connection is going strong, my computer is on ethernet cable, my ping is around 50ms, I'm averaging an internet speed of 800Mbps when DbD is not launched. I just dusted my entire computer to make sure it wasn't a hardware issue.

I have played 450+ hours of this game with the same setup over the last year, sometimes while watching my friend's streams, and never got disconnected once by lack of internet connection.

Since monday, I have been getting disconnected mid game 4 times : once on monday, then played a few hours without issue, twice yersterday and I was not able to play at all, and once today, in the first game I launched to see if it worked at a different time. (I haven't tried another game after)

Each time, there will be some intense lag and rubber banding going on at some random times, and at some point, the lag gets so much that I get disconnected. As I get disconnected, my whole computer briefly loses connection, which I noticed because it made me leave and immediately rejoin the Discord call I was on.

When I launch DbD, my internet speed slows down severely, to around 80Mbps (from 800Mbps), which I had never noticed but doesn't feel normal.

I literally can't play, and it's not on my computer's end, so I feel very powerless and frustrated to not be able to play the event.

I'm disinstalling and reinstalling, will update if it gets better or stays unchanged.

Edit : The 800Mbps is the value from when I have nothing demanding running on my computer, and no one home besides me. My internet speed when my computer is more active (watching streams, having youtube on) and while having other people at my house be equally active, is closer to 150Mbps.

Still, today's crash was when I was alone and with the fastest speeds.