I was getting this error constantly. Before, during and after matches in both multiplayer and Warzone. I tried all the fixes I found on line, port forwarding, firewall rules etc. No luck. I used PIA VPN, allowed the launcher and game through my anti virus. Still disconnects anywhere from every 15 mins to every hour. I also tried contacting my ISP and doubling my bandwidth, and drilling a hole through my floor to get an Ethernet cable direct to my PC. Nada
5 days ago I uninstalled Malwarebytes, hasn’t happened since. Nowhere I could find online suggested this so I hope it helps someone. It was getting to the point where the game was unplayable.