CoH2 is notoriously unoptimized for modern multi-core CPUs. To ensure your LAN doesn't crash mid-match:
Large replays can cause "Sync Errors" over local networks. Periodically clear your Documents/My Games/Company of Heroes 2/replays folder. company of heroes 2 lan updated
However, "LAN" in the modern context of CoH2 refers to , which minimizes external lag by routing data through your local switch once the handshake is made with Relic's servers. How to Set Up a CoH2 LAN Session (Updated Method) CoH2 is notoriously unoptimized for modern multi-core CPUs