Not sure if Arcade is using peer to peer or client server connections but it sounds like a NAT issue if only one of you can connect at a time. I would contact Ubi support.
EcVN1. ye7924i6nd.pages.dev/50ye7924i6nd.pages.dev/278ye7924i6nd.pages.dev/256ye7924i6nd.pages.dev/163ye7924i6nd.pages.dev/219ye7924i6nd.pages.dev/290ye7924i6nd.pages.dev/334ye7924i6nd.pages.dev/317ye7924i6nd.pages.dev/323
far cry 5 coop not working
