As you did not share your code, i think you have to specify match parent instead of wrap content for RecyclerView .

I have a RecyclerView that contains items entered in a dialog, the RV is also part of the dialog and the items appear as a button is pressed. The item is simply a LinearLayout TextView whose width matches the parent RV, and the text of the textview is centered.

The issue is that when I add a new item, they appear to be very far to the left. It is only when I scroll the item out of view and then bring it back to the items appear in the center. Also if I close the dialog and reopen it, the items then appear all in the correct alignment on reopening it. Still, if I add a new item, it will have the wrong alignment.

UPDATE: I changed the background color bc i realized the textview was just too small. I want the width to match the width of the RV, the text is properly centering but the TV is not filling the width of the RV… Here’s a pic:

See code below:

SpecAdapter.kt

    class SpecsAdapter(val context: Context, val specs: List<Specification>) :
    RecyclerView.Adapter<SpecsAdapter.ViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        return ViewHolder(LayoutInflater.from(context).inflate(R.layout.item_spec, parent, false))
    }

    override fun getItemCount() = specs.size

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val spec = specs[position]
        holder.bind(spec)
    }

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(spec: Specification) {
            itemView.tvSpec.text = "    ${spec.name}    "
            if (!spec.include) {
                itemView.tvSpec.apply {
                    paintFlags = Paint.STRIKE_THRU_TEXT_FLAG
                }
            }
        }
    }
}

Main Activity.kt (the part with the dialog where the RV appears)

fun showSpecificationDialog(specType: String) {
    val searchFormView = LayoutInflater.from(this).inflate(R.layout.specification_add, null)

    val dialog = AlertDialog.Builder(this)
        .setTitle("Include/Exclude")
        .setView(searchFormView)
        .setNeutralButton("Close", null)
        .show()

    dialog.findViewById<EditText>(R.id.etSearch)?.hint = "Enter $specType"

    val rvSpecs = dialog.findViewById<RecyclerView>(R.id.rvSpecs)
    val adapter = if (specType == "Ingredient") SpecsAdapter(this, ingredients) else SpecsAdapter(this, tags)
    rvSpecs?.adapter = adapter
    rvSpecs?.layoutManager = LinearLayoutManager(this)

    //clicking this adds the item to one of two lists, which appears in the recyclerview
    dialog.findViewById<Button>(R.id.btnInclude)?.setOnClickListener {
        val spec = dialog.findViewById<EditText>(R.id.etSearch)?.text.toString()
        if (specType == "Ingredient") {
            ingredients.add(Specification(spec, false, true))
            adapter.notifyItemInserted(ingredients.size - 1)
            Log.i(TAG, "added $spec to ingredients - exclude")
        } else {
            tags.add(Specification(spec, false, true))
            adapter.notifyItemInserted(tags.size - 1)
            Log.i(TAG, "added $spec to tags - exclude")
        }
        dialog.findViewById<EditText>(R.id.etSearch)?.setText("")
    }

    //clicking this adds the item to one of two lists, which appears in the recyclerview
    dialog.findViewById<Button>(R.id.btnExclude)?.setOnClickListener {
        val spec = dialog.findViewById<EditText>(R.id.etSearch)?.text.toString()
        if (specType == "Ingredient") {
            ingredients.add(Specification(spec, false, false))
            adapter.notifyItemInserted(ingredients.size - 1)
            Log.i(TAG, "added $spec to ingredients - include")
        } else {
            tags.add(Specification(spec, false, false))
            adapter.notifyItemInserted(tags.size - 1)
            Log.i(TAG, "added $spec to tags - include")
        }
        dialog.findViewById<EditText>(R.id.etSearch)?.setText("")
    }

    dialog.getButton(DialogInterface.BUTTON_NEUTRAL).setOnClickListener {
        dialog.dismiss()
    }
}

specification_add.xml (this holds the recyclerview and the buttons and whatnot)

<?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"
    xmlns_tools="http://schemas.android.com/tools"
    android_layout_width="match_parent"
    android_layout_height="match_parent">
    <EditText
        android_id="@+id/etSearch"
        android_layout_width="0dp"
        android_layout_height="wrap_content"
        android_layout_marginStart="24dp"
        android_layout_marginEnd="24dp"
        android_textAlignment="textStart"
        android_textSize="24sp"
        app_layout_constraintEnd_toEndOf="parent"
        app_layout_constraintStart_toStartOf="parent"
        app_layout_constraintTop_toTopOf="parent"
        tools_text="Ingredient/Tag" />

    <Button
        android_id="@+id/btnExclude"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
        android_layout_marginTop="8dp"
        android_text="Exclude"
        android_textSize="16sp"
        app_layout_constraintEnd_toEndOf="@id/etSearch"
        app_layout_constraintTop_toBottomOf="@+id/etSearch" />

    <Button
        android_id="@+id/btnInclude"
        android_layout_width="wrap_content"
        android_layout_height="wrap_content"
        android_layout_marginTop="8dp"
        android_text="Include"
        android_textSize="16sp"
        app_layout_constraintStart_toStartOf="@id/etSearch"
        app_layout_constraintTop_toBottomOf="@+id/etSearch" />

    <androidx.recyclerview.widget.RecyclerView
        android_id="@+id/rvSpecs"
        android_layout_width="0dp"
        android_layout_height="200dp"
        android_scrollbars="none"
        android_textAlignment="textStart"
        app_layout_constraintBottom_toBottomOf="parent"
        app_layout_constraintEnd_toEndOf="parent"
        app_layout_constraintStart_toStartOf="parent"
        app_layout_constraintTop_toBottomOf="@+id/btnInclude"
        app_layout_constraintVertical_bias="0.0" />
</androidx.constraintlayout.widget.ConstraintLayout>

item_add.xml (xml file for each individual item in RV)

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns_android="http://schemas.android.com/apk/res/android"
    xmlns_app="http://schemas.android.com/apk/res-auto"
    xmlns_tools="http://schemas.android.com/tools"
    android_layout_width="match_parent"
    android_layout_height="wrap_content">
    <TextView
        android_id="@+id/tvSpec"
        android_layout_width="match_parent"
        android_layout_height="wrap_content"
        android_padding="8sp"
        android_textAlignment="center"
        android_textColor="#000000"
        android_textSize="24sp"
        tools_text="Ingredient/Tag" />
</LinearLayout>