TextView appearing in preview but not on emulator and real device

I try to run my app in real device and facing this problem:

It looks like this in preview

It looks like this in emulator

Textview with id textViewSignUpForAccount is displaying in preview but not on emulator and real device.

what should be the problem?

I tried hours fixing this issue but no success.

here I am placing my code for the layout:

<?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"
    tools:context=".NotificationActivity">


    <RelativeLayout
        android:id="@+id/relativeLayout"
        android:layout_width="match_parent"
        android:layout_height="85dp"
        android:background="#FFFFFF"
        app:layout_constraintBottom_toTopOf="@id/linearLayout">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/notification_frag_toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentStart="true"
            android:background="@color/white"
            app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

            <TextView
                android:id="@+id/toolbar_title"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:layout_marginTop="45dp"
                android:text="All activity"
                android:textColor="@color/black"
                android:textSize="16sp" />

        </androidx.appcompat.widget.Toolbar>

        <View
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:layout_alignParentBottom="true"
            android:background="@color/iron" />
    </RelativeLayout>

    <LinearLayout
        android:id="@+id/linearLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:layout_marginTop="160dp"
        android:orientation="vertical"
        android:paddingLeft="24dp"
        android:paddingRight="24dp"
        app:layout_constraintTop_toBottomOf="@id/relativeLayout" >

        <ImageView
            android:id="@+id/imageViewProfileIcon"
            android:layout_width="wrap_content"
            android:layout_height="72dp"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="2dp"
            android:layout_marginBottom="12dp"
            android:src="@drawable/inboxicon" />

        <TextView
            android:id="@+id/textViewSignUpForAccount"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="10dp"
            android:gravity="center"
            android:text="Messages and notifications will appear here"
            android:textAllCaps="false"
            android:textSize="16sp" />


        <!-- Signup Button -->
        <androidx.appcompat.widget.AppCompatButton
            android:id="@+id/btn_signup_in_notificationsActivity"
            android:layout_width="290dp"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_marginTop="5dp"
            android:layout_marginBottom="24dp"
            android:background="@color/primary"
            android:padding="12dp"
            android:text="Sign up"
            android:textAllCaps="false"
            android:textColor="@color/white" />

    </LinearLayout>


    <FrameLayout
        android:id="@+id/container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_constraintBottom_toTopOf="parent"
        app:layout_constraintTop_toBottomOf="@id/linearLayout">
        <!-- Main content -->
        <com.google.android.material.bottomnavigation.BottomNavigationView
            android:id="@+id/bottom_navigation"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="bottom"
            android:background="@color/primary"
            app:itemIconTint="@drawable/selector"
            app:itemTextColor="@drawable/selector"
            app:labelVisibilityMode="labeled"
            app:menu="@menu/bottom_navigation_menu" />
    </FrameLayout>

</androidx.constraintlayout.widget.ConstraintLayout>