Microsoft MakeCode

Problem with pxt-sample

I would like to build my own PXT with really few visual blocks. I would like to run it locally.
I tried to document myself and this is what I’ve done

I think I was able to install and run pxt-microbit following these steps:
cd /d/GitHub
git clone https://github.com/Microsoft/pxt-microbit
cd /d/GitHub/pxt-microbit
npm install -g pxt
npm install
cd /d/pxt_projects (should I need to go outside /d/GitHub/pxt-microbit folder ?)
pxt target microbit
pxt serve

It opens a local server where I can see the micro:bit interface like https://makecode.microbit.org/
The projects are saved inside my folder /d/pxt_projects

So my second step was to use pxt-sample and then start customizing it… but…
cd /d/GitHub
git clone https://github.com/Microsoft/pxt-sample
cd /d/GitHub/pxt-sample
npm install -g pxt
npm install
cd /d/pxt_projects
pxt target sample
pxt serve

It opens the browser but I can see only the following image and nothing happens.
PXT

What am i doing wrong?

I tried the pxt-sample as well, like this:

git clone https://github.com/microsoft/pxt-sample
cd pxt-sample
npm install
npm install -g pxt // note: pxt was probably already installed from earlier
pxt serve --local

There are errors in the console, and many icons are missing in the editor. I wonder whether pxt-sample still works with the current pxt ?