visual studio code time out when jump server connecting target server

Question

I need to connect the target server only via a jump server. I can connect the jump server. But when the jump server connecting the target server, there is a popup window：Could not establish connection to "TargetMachine": The connection timed out. Before that, the vs code is always Setting up SSH Host TargetMachine: (details) Initializing VS Code Server.

my computer is Mac and more information is:

[18:49:26.861] Log Level: 2
[18:49:26.862] remote-ssh@0.82.1
[18:49:26.862] darwin arm64
[18:49:26.864] SSH Resolver called for "ssh-remote+7b22686f7xxxxxxxxxx", attempt 1
[18:49:26.864] "remote.SSH.useLocalServer": false
[18:49:26.864] "remote.SSH.showLoginTerminal": false
[18:49:26.865] "remote.SSH.remotePlatform": {}
[18:49:26.865] "remote.SSH.path": undefined
[18:49:26.865] "remote.SSH.configFile": undefined
[18:49:26.865] "remote.SSH.useFlock": true
[18:49:26.865] "remote.SSH.lockfilesInTmp": false
[18:49:26.865] "remote.SSH.localServerDownload": auto
[18:49:26.865] "remote.SSH.remoteServerListenOnSocket": false
[18:49:26.866] "remote.SSH.showLoginTerminal": false
[18:49:26.866] "remote.SSH.defaultExtensions": []
[18:49:26.867] "remote.SSH.loglevel": 2
[18:49:26.867] "remote.SSH.enableDynamicForwarding": true
[18:49:26.867] "remote.SSH.enableRemoteCommand": false
[18:49:26.867] "remote.SSH.serverPickPortsFromRange": {}
[18:49:26.867] "remote.SSH.serverInstallPath": {}
[18:49:26.874] SSH Resolver called for host: TargetMachine
[18:49:26.874] Setting up SSH remote "TargetMachine"
[18:49:26.876] Using commit id "30d9c6cdxxxxxxxxxx" and quality "stable" for server
[18:49:26.878] Install and start server if needed
[18:49:27.602] PATH: /Users/songjia/.gem/ruby/3.1.1/bin:/Users/songjia/.gem/ruby/X.X.0/bin:/usr/local/opt/ruby/bin:/Users/songjia/.gem/ruby/3.1.1/bin:/Users/songjia/.rubies/ruby-3.1.1/lib/ruby/gems/3.1.0/bin:/Users/songjia/.rubies/ruby-3.1.1/bin:/opt/homebrew/Caskroom/miniforge/base/bin:/opt/homebrew/Caskroom/miniforge/base/condabin:/opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/songjia/.rvm/bin
[18:49:27.602] Checking ssh with "ssh -V"
[18:49:27.611] > OpenSSH_8.1p1, LibreSSL 2.7.3

[18:49:27.612] Running script with connection command: ssh -T -D 56756 -o ConnectTimeout=40 'TargetMachine' bash
[18:50:07.950] > Connection timed out during banner exchange
[18:50:07.950] Got some output, clearing connection timeout
[18:50:08.069] "install" terminal command done
[18:50:08.070] Install terminal quit with output: Connection timed out during banner exchange
[18:50:08.070] Received install output: Connection timed out during banner exchange
[18:50:08.073] Resolver error: Error: The connection timed out
    at Function.Offline (/Users/songjia/.vscode/extensions/ms-vscode-remote.remote-ssh-0.82.1/out/extension.js:1:585270)
    at /Users/songjia/.vscode/extensions/ms-vscode-remote.remote-ssh-0.82.1/out/extension.js:1:582845
    at Object.t.handleInstallOutput (/Users/songjia/.vscode/extensions/ms-vscode-remote.remote-ssh-0.82.1/out/extension.js:1:583059)
    at Object.t.tryInstall (/Users/songjia/.vscode/extensions/ms-vscode-remote.remote-ssh-0.82.1/out/extension.js:1:680958)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async /Users/songjia/.vscode/extensions/ms-vscode-remote.remote-ssh-0.82.1/out/extension.js:1:643905
    at async Object.t.withShowDetailsEvent (/Users/songjia/.vscode/extensions/ms-vscode-remote.remote-ssh-0.82.1/out/extension.js:1:647221)
    at async Object.t.resolve (/Users/songjia/.vscode/extensions/ms-vscode-remote.remote-ssh-0.82.1/out/extension.js:1:644955)
    at async /Users/songjia/.vscode/extensions/ms-vscode-remote.remote-ssh-0.82.1/out/extension.js:1:727005
[18:50:08.085] ------

I can't find what causes this problem.