Paging adapter unable to receive updated data - kotlin

Question

I am currently building a fragment, and within the fragment contains 2 paging adapter sharing the same data. When I update the data, only one of the paging adapter receives the updated data while the other does not.
On first start up. for reference (backdrop - top adapter/viewpager, poster - bottom adapter/viewpager)
first item =
second item =
third item =
when I change the movie category, only the bottom paging adapter receive the updated data
updated first item =
updated second item =
updated third item =
as seen in the image, the bottom paging adapter have successfully updated its image while the top paging adapter does not
additional information:
I am using Remote Mediator to store network data to ROOM Database.
Both top and bottom list is displayed using viewpager2, page transformer is applied to both viewpager. To add on, top viewpager scroll is dependent on the bottom viewpager (i.e. top viewpager will only scroll if bottom view pager scrolls).
depending on which paging adapter's submitData function is called first, its data will be updated, while the paging adapter after it won't update its data.
for the case below, the bottom viewPager(poster) will be updated while the top viewPager(backdrop) won't be updated.
collectLatestLifecycleFlow(viewModel.movieList) { pagingData ->
posterPagingAdapter.submitData(pagingData)
backdropPagingAdapter.submitData(pagingData)
}
I expect both paging adapter to be updated when I update the movie category.
so far as a temporary solution I created two flow collectors to collect the data so that both viewpager can update their data, however this is inefficient as it will do another Api Call which is redundant.
collectLatestLifecycleFlow(viewModel.movieList) { pagingData ->
backdropPagingAdapter.submitData(pagingData)
}
collectLatestLifecycleFlow(viewModel.movieList) { pagingData ->
posterPagingAdapter.submitData(pagingData)
}
below is the code I use to in ViewModel to get the data
val movieList = selectedMovieCategory.flatMapLatest {
Timber.i("selected category: $it")
when (it) {
MoviePagingCategory.NOW_PLAYING.categoryName -> {
moviesUseCase.getNowPlayingPagingData(loadSinglePage = true)
}
MoviePagingCategory.POPULAR.categoryName -> {
moviesUseCase.getPopularMoviesPagingData(loadSinglePage = true)
}
MoviePagingCategory.TRENDING.categoryName -> {
moviesUseCase.getTrendingMoviesPagingData(loadSinglePage = true)
}
else -> throw Exception("No listed category")
}.cachedIn(viewModelScope)
}
for PagingAdapter's diff util. do note that id here is a manually generated id instead of movieId provided by the Api. the reason for this is to store multiple movie types in single room table.
companion object DiffUtilCallback : DiffUtil.ItemCallback<Result>() {
override fun areItemsTheSame(oldItem: Result, newItem: Result): Boolean {
return oldItem.id == newItem.id
}
override fun areContentsTheSame(oldItem: Result, newItem: Result): Boolean {
return oldItem == newItem
}
}