The xml below in Nougat is ignoring the marginLeftPercent.
<?xml version="1.0" encoding="utf-8"?>
<android.support.percent.PercentRelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/inBoxButton"
app:layout_widthPercent="20%"
app:layout_marginLeftPercent="30%"
app:layout_marginTopPercent="2%"
android:layout_height="40dp"
android:text="Inbox"
android:textSize="18sp"
android:tag="1"
android:lines="1"
android:gravity="center"
android:textColor="@color/black_color"
/>
I have other places in my app where it's not ignored, but those other places do not have layout_widthPercent. This works fine in 6.0, but I think it's a bug in 7.0.