java - RecyclerView creates margins when scrolling sometimes -

recyclerview creates margin comes out after scrolling , down. doesn't occur items occur same item.

edit: margins marked black circles bigger green ones. supposed have same space between each items

and here xml code

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingbottom="@dimen/activity_vertical_margin" android:paddingleft="@dimen/activity_horizontal_margin" android:paddingright="@dimen/activity_horizontal_margin" tools:context="com.mangolassi.norman.steller.messageroomactivity">  <android.support.v7.widget.recyclerview      android:id="@+id/messagerecyclerview"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_above="@+id/linearlayout"/>  <linearlayout     android:id="@+id/linearlayout"     android:layout_width="match_parent"     android:layout_height="wrap_content"     android:layout_alignparentbottom="true"     android:layout_alignparentleft="true"     android:layout_alignparentstart="true"     android:orientation="horizontal">      <edittext         android:id="@+id/messageedittext"         android:layout_width="0dp"         android:layout_height="wrap_content"         android:layout_gravity="center_vertical"         android:layout_weight="1"/>      <button         android:id="@+id/sendbutton"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_gravity="bottom"         android:enabled="false"         android:text="send"/>  </linearlayout> 

and here item xml

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical">  <relativelayout     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:gravity="center_vertical"     android:orientation="horizontal">      <linearlayout         android:layout_width="wrap_content"         android:layout_height="wrap_content">          <de.hdodenhof.circleimageview.circleimageview             android:id="@+id/useravatar"             android:layout_width="46dp"             android:layout_height="46dp"             android:layout_marginleft="10dp"             android:src="@mipmap/default_avatar"             />          <textview             style="@style/incomingmessage"             android:id="@+id/messagetextview"             android:text="bsp"             android:layout_width="wrap_content"             android:layout_height="wrap_content"             />      </linearlayout>     <textview         style="@style/outgoingmessage"         android:id="@+id/messagetextview2"         android:text="bsp"         android:layout_width="wrap_content"         android:layout_height="wrap_content" />  </relativelayout> </linearlayout> 

im using latest android studio