Code after `pagingAdapter.submitData()` is not executed

I am writing a toy Android app using Kotlin flow and Android Paging 3 library. The app calls some remote API to get a list of photos, and display them using a RecyclerView with a PagingDataAdapter.

I find that the code after pagingAdapter.submitData() is not executed.

Here is the code snippet (this function is in a Fragment):

  fun refreshList() {
    lifecycleScope.launch {
      photosViewModel.listPhotos().collect {
        // `it` is PagingData<Photo>
        pagingAdapter.submitData(it)
        Log.e(TAG, "After submitData")
      }
    }
  }

The log After submitData is not printed.

However, if I put the logging in front of the pagingAdapter.submitData() line, it is printed, like this:

  fun refreshList() {
    lifecycleScope.launch {
      photosViewModel.listPhotos().collect {
        // `it` is PagingData<Photo>
        Log.e(TAG, "Before submitData")
        pagingAdapter.submitData(it)
      }
    }
  }

The log Before submitData is printed with no problem.

Why does this happen, please?