before() does not synchronize on a nested describe()

My tests require a promise to be resolved before they start. I have the following:

• before() hook with the asynchronous call
• a test on the same level as the before() hook
• a group of level 2 tests grouped in a nested describe()

The level1 test is correctly synchronized on the promise in the before() hook. However the describe() group is not. Why not and how to synchronize it?

describe('My tests)=> {

  const thePromise$ = (asynchronous call here)

  before(async () => await thePromise$)

  beforeEach(async () => await thePromise$) //an extra safeguard?

  if('Test Level1', ()=> {
   console.log('Test1')
   //won't start until thePromise$ is resolved, excatly as I want
  })

  describe('Level2 Test group', ()={
    console.log('Level2 test group')
    //starts right away, does not wait for the promise to be resolved
  })
})