To add to @jkuester’s answer above:
It might not be immediately clear that the user properties being referenced in the form expression are actually sourced from the user’s associated contact document.
For example, if your user’s role (visible in the user management) is chw, but the associated contact does not have a field named role with value chw, it will not work as expected. In that case, please make sure that you have the correct role in the contact document too.