It seems your son got hit with lag switchers/drophackers, or possibly DDoS if your entire internet went out. Note that Crucible will auto-ban you for 30 min if you keep 'quitting' Competitive and Gambit matches (especially if a you have a high ratio of 'quitting' versus matches successfully completed, but unfortunately, the game literally cannot tell the difference between someone who 'rage-quit' versus someone who was playing against cheaters and the cheaters used a hardware or software lag switch to lag them out of the game or force-disconnected them from the match entirely, due to the nature of Destiny 2's 'hybrid peer-to-peer' network code which reveals your IP address to all other players you interact with on Destiny 2. For the sake of your home internet connection, I highly recommend subscribing to a reputable VPN service: if on console, you can either pipe your console's internet through a Windows or Mac computer with two ethernet adapters (or one ethernet and one WiFi connection, like on a laptop), using Internet Connection Sharing (or the Mac equivalent), and then run VPN software on the computer. This will also allow you to monitor network traffic to and from your console via other software like Wireshark and Net Limiter (the latter which is popular for lag switchers and drophackers). The alternative is to purchase a VPN-ready router with custom firmware pre-flashed onto the router, from vendors like flashrouters.com. While all this will not prevent lag switchers, drophackers, it will protect your home internet from being repeatedly disconnected by sore losers who may attempt DDoS attacks (Distributed Denial of Service) when they lose in the game (DDoS attacks are considered federal cyber crimes and investigated by the FBI and Europol, but that hasn't really stopped cheaters from doing it, or from criminals offering DDoS-for-hire 'booter'/'stresser' sites). More info here: https://www.pcgamer.com/the-strange-science-of-destiny-2s-uniquely-complicated-netcode/ https://venturebeat.com/2018/05/13/why-the-game-industry-is-still-vulnerable-to-distributed-denial-of-service-attacks/ https://www.gamerevolution.com/news/355113-bungies-response-destiny-2s-ddos-attacks-angered-community https://techcrunch.com/2018/12/20/fbi-ddos-booter-sites-offline/ https://www.forbes.com/sites/leemathews/2019/01/29/law-enforcement-agencies-are-going-after-hundreds-of-ddos-users/ https://www.techadvisor.co.uk/how-to/game/use-vpn-ps4-3670694/ https://www.windowscentral.com/use-vpn-xbox-one https://www.healthcareitnews.com/news/feds-warn-ddos-attack-vulnerability-connected-medical-devices https://www.techradar.com/vpn/best-gaming-vpn