Unable to set default app for user environment in TLJH

Hello.
I’ve run into issue where I’m unable to set user environments default app to jupyterlab.
My current approach was to add it to config with commands shown in documentation as:

sudo tljh-config set user_environment.default_app jupyterlab

Also i tried to do it manually on /opt/tljh/config/config.yaml, but no luck - I did tljh-config reload, and even server machine restart, but still get /tree as startup page, of course I’m able to swap url manually to /lab, but that is not expected workflow for other users on my server.

My current configuration (obfuscated):

users:
  admin:
  - xxx-admin
  - name.surname@domain.com
https:
  enabled: true
  letsencrypt:
    email: email@email.com
    domains:
    - xxx.domain.com
services:
  cull:
    every: 3600
    timeout: 3600
    max_age: 0
    users: false
    enabled: false
user_environment:
  default_app: jupyterlab

Any leads where i should look further?
Thanks a lot for help, hope to see some answers.

Regards,
ReWin