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Gaps in between recyclerview items when view inside item is shown/hidden

I am using recycler view with linear layout manager, based on some logic I am hiding/showing a view inside recycler view item.
Issue Problem occurs when I scroll, I can see some gaps in between recycler view item, which are random when scroll. If I hide the view always , then there is no issue, but I need to show and hide based on some logic and when implemented the gaps are coming as well.
Assumption One thing I am sure of is that the issue is there because of hiding/showing a view.

Impelement two recyclerview in one screen

How can I implement this kind of UI, where we have two recyclerViews. One scrolls horizontally and the second one vertically. when the second one scrolls first one also scrolls top together.
I tried to implement using NestedScrollView, but I had to make second recyclerView height wrap content which causes recyclerView not recycle.
The second way that I tried was having one recyclerView. And adding horizontal recyclerview as a header. The problem was to save header recyclerview scroll state when navigation. And there had been crashes when loading next page (paging 3) in header recyclerView.
The question is: Is there any optimal solution for this kind of ui?

In cases, Like this, you don't have to use 2 RecyclerView and you also have to avoid using RecyclerView insideScrollView. instead of this you have to use one vertical RecyclerView with multitype view Adapter.
in this way, you are going to have 2 different ViewHolder one of them is a horizontal recyclerView (your top item) and the other one is your other items.
for learning multitype adapter you can see this:
How to create RecyclerView with multiple view types
and for a horizontal recyclerView inside a vertical RecyclerView you can see this :
https://medium.com/#ashishkudale/android-list-inside-list-using-recyclerview-73cff2c4ea95
you have to combine these 2.
I could not understand the meaning of "header" where you said "adding horizontal recyclerview as a header" but if you did what I told and the problem is the state of inner Horizontal recyclerView, I think probably you are calling setAdapter method of horizontal RecyclerView in OnBind() method of your vertical recycler view, it is a common mistake that I have seen in many tutorials.
if you have done this mistake , try to call setAdapter of your inner recyclerView in the constructor of its viewHolder and just update the list using yourHorizontalAdapter.notifyDataSetChanged() in onBind() method of VerticalRecylerView,
and if its not the case and your recyclerView is completely destroying see this link :How to save RecyclerView's scroll position using RecyclerView.State?

Android RecyclerView scrolls to top when child element is expanded/collapsed

I have a list of elements in a recycler view that are generated dynamically using data binding. Each element has a bottom view that is initially set to View.GONE, however once a user clicks the element and the view is expanded, the recycler view automatically scrolls back to the top of the list. Conversely, if the view is expanded and then clicked again to collapse, the recycler view scrolls to the top of the list again. I have tried keeping track of the ID's of the elements for the adapter (again using data binding), setting focus to the child element when they expand or collapse, and using binding adapters to animate the expand/collapse itself.
My suspicion is that the adapter in the recycler view is receiving a onNotifyDataChanged() alert when the height of one of the child changes, rendering an additional view (still inside one of the children though, not a separate child in the list), and automatically scrolls to the top. Is there a way to override this? Does anyone know what else might be causing the list to snap to the top when one of the elements is clicked -> expanded/collapsed?

So I found the solution to my issue in case someone encounters something similar. I actually ended up finding this answer: RecyclerView notifyDataSetChanged scrolls to top position
and the second solution involving the staggered layout manager was the route I went with, since I want to be able to wrap the content. My suspicions were correct that it had to do with the changing height of the elements in the recycler view. The expandable item's parent wrapped content, so the recycler view was forced to recalculate the size of the item once the expandable portion appeared/disappeared (at least that's what I got out of it).

Vertical RecyclerView containing nested RecyclerView

Structure of my Android app is forcing me to create Vertical Nested RecyclerView inside Vertical Nested RecyclerView because of the pre-drawing all nested items inside every RootRecyclerView. The View of RootRecyclerView has approximately 5 - 10 views and the View of InsideRecyclerView consists also from 5-10 views. There is not necessarity for scrolling this ChildRecyclerView, because all scrolling is handled by RootRecyclerView (same term as Nested RecyclerView)
I have two options:
1. ChildRecyclerView, that will predraw all child items when the root item will reached the screen (it lags, but the result looks good under the 30 child rows)
2. Join the Root+Child View, remove Child RecyclerView and the all logic will be handled in the Root RecyclerView. - i tried this, also used ConstraintLayout, so the whole layout was only 1-LEVEL, but it was still laggy, even if I set Visibility of half of the views in this layout. I also setup setHasFixedSize(true), tried to use Cache methods of RecyclerView, initialCacheItemSize and so on.
So do you have any ideas, how to solve this problem? Did somebody of you met with this kind of problem? You could also imagine the case of ChildRecyclerView inside another ChildRecyclerView that is inside RootRecyclerView.

Memory efficient list for android

I have a list of about 100 items. In each list item I need a framelayout with 2 relative layouts. When a button called "Flip" is clicked then one relative layout will flip out and the other relative layout will flip in. And each item has full width of the screen. So, I need to show the item in a horizontal scroll view. Now, I want to keep at most 3 items every moment. When user scrolls to the first item then we have to update the 3 items. The first item will be the 2nd item. And we have to add another item at the front. In this way we have to update the items when user scrolls to the last item. I have tried many ways. I have used Gallery for the horizontal scroll view. And used the onItemSelected method. But, if I scroll the Gallery fast then it crashes. So, please someone help me to implement the 3 items idea.

It sounds like you need a ListView. Is there a reason you are trying to reinvent it?
Also don't you mean a vertical scroll view? Why are using a horizontal?