Vertical RecyclerView nested inside vertical RecyclerView

I have spent hours/days reading around this subject but still can't find something that works. I'm trying to put a fixed-height vertically-scrolling RecyclerView in the row of another vertically-scrolling RecyclerView.

Much of the advice is along the lines of "it's a crime to put a vertically-scrolling RecyclerView inside another vertically-scrolling RecyclerView"... but I can't figure out why this is so bad.

In fact, the behaviour would be almost exactly the same as many pages on StackOverflow (e.g. this one... and indeed this very question, at least when viewed on a mobile device), where the code sections are of a fixed (or max) height, and scroll vertically, and are contained within a page that itself scrolls vertically. What happens is that when focus is on the code section, scrolling happens within that section, and when it reaches the upper/lower end of the scroll range of the section, then scrolling happens within the outer page. It's quite natural, not evil.

This is my recycler_view_row_outer.xml (a row within the outer RecyclerView):

<com.google.android.material.card.MaterialCardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    style="@style/MyCardView"
    app:cardElevation="4dp"
    app:strokeColor="?attr/myCardBorderColor"
    app:strokeWidth="0.7dp"
    card_view:cardCornerRadius="8dp" >

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <TextView
            style="@style/MyTextView.Section"
            android:id="@+id/list_title" />

        <LinearLayout
            style="@style/MyLinearLayoutContainer"
            android:id="@+id/list_container"
            android:layout_below="@+id/list_title" >
        </LinearLayout>

    </RelativeLayout>

</com.google.android.material.card.MaterialCardView>

And this is my recycler_view_row_inner.xml (a row within the inner RecyclerView):

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/my_constraint_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/list_container" >

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycler_view_inner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scrollbarStyle="outsideOverlay"
        android:scrollbars="vertical"
        app:layout_constrainedHeight="true"
        app:layout_constraintBottom_toBottomOf="@+id/my_constraint_layout"
        app:layout_constraintEnd_toEndOf="@+id/my_constraint_layout"
        app:layout_constraintHeight_max="750dp"
        app:layout_constraintHeight_min="0dp"
        app:layout_constraintStart_toStartOf="@+id/my_constraint_layout"
        app:layout_constraintTop_toTopOf="@+id/my_constraint_layout" >
    </androidx.recyclerview.widget.RecyclerView>

</androidx.constraintlayout.widget.ConstraintLayout>

With the above inner layout, I've tried to follow the approach set out in this post, to create an inner RecyclerView having a fixed/max height... but it isn't working.

I inflate the inner layout (added to list_container/containerView in the outer layout) and set up my inner recyclerView as follows:

View inflatedView = getLayoutInflater().inflate(R.layout.recycler_view_row_inner, containerView, false);
RecyclerView recyclerView = inflatedView.findViewById(R.id.recycler_view_inner);
// set adapter, row data, etc

But all this does is create a fixed-height inner row that does not scroll within the outer row... overflow content of the inner row is just cut off and I can't reach the lower part of it because it just scrolls the outer row.

Any idea how to make this work?

from Vertical RecyclerView nested inside vertical RecyclerView