Extension are not installed when configured in devcontainer.json

• VSCode Version: 1.53.1
• Local OS Version: Windows 10
• Remote OS Version: Ubuntu:focal - official Microsoft container
• Remote Extension/Connection Type: Docker
• Logs:
  During the built phase:

53980 ms] Start: Run in container: test -d /home/vscode/.vscode-server/extensionsCache && ls /home/vscode/.vscode-server/extensionsCache || true
[53986 ms] 
[53986 ms] 
[53987 ms] Start: Run in container: test -d /vscode/vscode-server/extensionsCache && ls /vscode/vscode-server/extensionsCache || true
[53990 ms] 
[53991 ms] 
[53992 ms] Start: Run in container: for pid in `cd /proc && ls -d [0-9]*`; do { echo $pid ; readlink /proc/$pid/cwd ; readlink /proc/$pid/ns/mnt ; cat /proc/$pid/stat | tr "
[54085 ms] Start: Starting VS Code Server
[54086 ms] Start: Run in container: /home/vscode/.vscode-server/bin/5d424b828ada08e1eb9f95d6cb41120234ef57c7/server.sh --force-disable-user-env --use-host-proxy --port 0 --extensions-download-dir /home/vscode/.vscode-server/extensionsCache --install-extension ms-vscode.azure-account --install-extension ms-kubernetes-tools.vscode-aks-tools --install-extension ms-azure-devops.azure-pipelines --install-extension tomaustin.azure-devops-yaml-pipeline-validator --install-extension ms-azuretools.vscode-azureterraform --install-extension rogalmic.bash-debug --install-extension mindaro.mindaro --install-extension adamvoss.vscode-languagetool-en --install-extension waderyan.gitblame --install-extension donjayamanne.git-extension-pack --install-extension donjayamanne.githistory --install-extension codezombiech.gitignore --install-extension eamodio.gitlens --install-extension hashicorp.terraform --install-extension ms-kubernetes-tools.vscode-kubernetes-tools --install-extension ipedrazas.kubernetes-snippets --install-extension adamvoss.vscode-languagetool --install-extension yzhang.markdown-all-in-one --install-extension bierner.markdown-mermaid --install-extension timonwong.shellcheck --start-server
[55031 ms] 

So apparently no error occurs, but no extension is installed. I checked Inside the container

$ ls -al /home/vscode/.vscode-server/extensions/
total 8
drwxr-xr-x 2 vscode vscode 4096 Sep 22 07:31 .
drwxr-xr-x 5 vscode vscode 4096 Sep 22 07:31 ..

But from the logs I see that a different dir is checked /home/vscode/.vscode-server/extensionsCache or /vscode/vscode-server/extensionsCache. Neither of them exists
Steps to Reproduce:

1. Rebuild the container
2. The extension are not installed
3. But manually I can install them inside the container

ls -al /home/vscode/.vscode-server/extensions/
total 12
drwxr-xr-x 3 vscode vscode 4096 Sep 22 07:38 .
drwxr-xr-x 5 vscode vscode 4096 Sep 22 07:31 ..
drwxr-xr-x 6 vscode vscode 4096 Sep 22 07:38 ms-vscode.azure-account-0.9.8

Does this issue occur when you try this locally?: No
Does this issue occur when you try this locally and all extensions are disabled?: Yes