Remote connection to localhost not working

[rashil2000]

I run nvim --headless --listen localhost:6666 in one terminal, and fvim --nvr localhost:6666 in another. But this gives me an error:

Exit code: 0
Exception message: No connection could be made because the target machine actively refused it. 127.0.0.1:6666

at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress) at System.Net.Sockets.Socket.Connect(EndPoint remoteEP) at FVim.neovim.Nvim.createIO(ServerOptions serveropts) in D:\a\1\s\neovim.fs:line 65 at FVim.neovim.Nvim.start(ServerOptions opts) in D:\a\1\s\neovim.fs:line 101 at FVim.model.Start(ServerOptions serveropts, Boolean norc, Boolean debugMultigrid) in D:\a\1\s\model.fs:line 144 at FVim.Program.startMainWindow(FSharpFunc`2 app, ServerOptions serveropts_0, Boolean serveropts_1, Boolean serveropts_2) in D:\a\1\s\Program.fs:line 59 at FVim.Program.Main(String[] args) in D:\a\1\s\Program.fs:line 138

I have tried doing pip install neovim-remote too, but it doesn't help.

[OS: Windows 10]

[rashil2000]

This is really strange, but changing the first command to nvim --headless --listen 127.0.01:6666 works fine.