I'm encountering the same issue. iOS 15 beta, tvOS 15 beta, and matter/chip profiles are installed on both devices. Failed to add and set up accessories for topology: Error Domain=HMErrorDomain Code=48 "(null)"

I just tried out iOS beta 4 and XCode beta 4 and this is no longer an issue. Thank you for the fix!

Looks like it was updated to HMMatterHome in iOS 15.2

Hoping to revive this thread. I'm getting NWEndpoint from NWBrowser and trying to force IPv4. let parameters = NWParameters.udp parameters.includePeerToPeer = true (parameters.defaultProtocolStack.internetProtocol! as! NWProtocolIP.Options).version = .v4 But checking to see if parameters.defaultProtocolStack.internetProtocol! as! NWProtocolIP.Options).version == .v4 returns false. It doesn't seem to be setting the version as expected. I checked and it remains as any. It seems like NWProtocolUDP.Options() and NWProtocolTLS.Options() initializers exist but NWProtocolIP.Options does not have an init exposed so I can't try setting params.defaultProtocolStack.internetProtocol = NWProtocolIP.Options() // and set version on options before assigning here