android - Android Studio 3.1 アップデートでキーパッドを開くとアプリがフリーズする

Question

アプリはアップデート前は正常に動作していました。カーソルをクリックするたびEditTextに、アプリがフリーズしてスタックするよりも、数秒間点滅します。

login_activity.xml

<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="match_parent"
    android:background="@color/white"
    android:focusable="true"
    android:focusableInTouchMode="true"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    tools:context=".activities.LoginActivity">

       <app.com.skribl.utils.customviews.CustomTILayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="@dimen/_20sdp"
                android:gravity="center"
                android:textColorHint="@color/orange"
                app:customFont="Raleway-Regular.ttf">

                <app.com.skribl.utils.customviews.CustomEditText
                    android:id="@+id/et_email"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:gravity="center"
                    android:hint="@string/prompt_email1"
                    android:inputType="textEmailAddress"
                    android:maxLines="1"
                    android:padding="@dimen/x13dp"
                    android:singleLine="true"
                    android:textColor="@color/blue_dark"
                    android:textSize="14sp"
                    app:customFont="Roboto-Light.ttf" />
            </app.com.skribl.utils.customviews.CustomTILayout>

            <app.com.skribl.utils.customviews.CustomTILayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="@dimen/_5sdp"
                android:gravity="center"
                android:textColorHint="@color/orange"
                app:customFont="Raleway-Regular.ttf">

                <app.com.skribl.utils.customviews.CustomEditText
                    android:id="@+id/et_password"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:gravity="center"
                    android:hint="@string/prompt_password"
                    android:inputType="textPassword"
                    android:maxLines="1"
                    android:padding="@dimen/x13dp"
                    android:singleLine="true"
                    android:textColor="@color/blue_dark"
                    android:textSize="14sp"
                    app:customFont="Roboto-Light.ttf" />

            </app.com.skribl.utils.customviews.CustomTILayout>

            <app.com.skribl.utils.customviews.CustomButton
                android:id="@+id/btn_login"
                style="?android:textAppearanceSmall"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="@dimen/_20sdp"
                android:background="@drawable/round_corner_btn"
                android:padding="@dimen/x15dp"
                android:text="@string/action_sign_in_short"
                android:textColor="@color/white"
                android:textSize="@dimen/text_size_moderate"
                android:textStyle="bold"
                app:customFont="Raleway-Regular.ttf" />

        </LinearLayout>

CustomEditText.java

public class CustomEditText extends EditText {
    private static final String TAG = "EditText";

    public CustomEditText(Context context) {
        super(context);
    }

    public CustomEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        setCustomFont(context, attrs);
    }

    public CustomEditText(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setCustomFont(context, attrs);
    }

    private void setCustomFont(Context ctx, AttributeSet attrs) {
        TypedArray a = ctx.obtainStyledAttributes(attrs, R.styleable.CustomTextView);
        String customFont = a.getString(R.styleable.CustomTextView_customFont);
        setCustomFont(ctx, customFont);
        a.recycle();
    }


    public boolean setCustomFont(Context ctx, String fontName) {
        Typeface typeface = null;
        try {
            if(fontName == null){
                fontName = Constants.DEFAULT_FONT_NAME_FOR_ET;
            }
            typeface = Typeface.createFromAsset(ctx.getAssets(), "fonts/" + fontName);
        } catch (Exception e) {
            Log.e(TAG, "Unable to load typeface: "+e.getMessage());
            return false;
        }

        setTypeface(typeface);

        return true;
    }

    protected void setSpan_internal(Object span, int start, int end, int flags) {
        final int textLength = getText().length();
        ((Editable) getText()).setSpan(span, start, Math.min(end, textLength), flags);
    }

    protected void setCursorPosition_internal(int start, int end) {
        final int textLength = getText().length();
        Selection.setSelection(((Editable) getText()), Math.min(start, textLength), Math.min(end, textLength));
    }

}

これまでのログは次のとおりです。

java.lang.NullPointerException: Attempt to invoke interface method 'void android.view.inputmethod.InputConnection.closeConnection()' on a null object reference at android.view.inputmethod.InputConnectionWrapper.closeConnection(InputConnectionWrapper.java:270)
        at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper.java:553)
        at com.android.internal.view.IInputConnectionWrapper$MyHandler.handleMessage(IInputConnectionWrapper.java:93)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6119)
        at java.lang.reflect.Method.invoke(Native Method)
        atcom.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)