too high network latency between local client and local server.

I'm testing my game with 2 local instances of game

Client joins server using unity providing matchmaker.

The problem is, when server sends any network packets to client (using SyncVar, NetworkMessages, ClientRPC. i tested them all), it takes almost more than 100ms for packet to arrive client. (Measured with Network.time) and it's too long time for my game because it's realtime multiplayer game.

Is the packet goes through some kind of unity master server to find client?

I don't know why it takes too long time even though remote client is in same local computer with server.

any idea to reduce client reponse time? i don't know if direct connection to server solves problem, not using matchmaker.

or should I use LLAPI? I don't know how unity handles those HLAPI packets under the hood.