Once the app loaded, text "Selected: null" will not show

Testsuite name: FXCompatibilityManual
Test name(s): graphics/api/control/treeview/TreeViewTest08Test.java
Product(s) tested: JDK9b126 (64bit)
OS/architecture: Ubuntu16.04-x64

Reproducible: Always
Reproducible on machine: Evergreen-machine
[If Sometimes] Also reproducible on machine:

Is it a Regression:No
(Test on ubuntu16.04-x64 with jdk9b178-64bit,the results:failed as the same issue)
(Test on ubuntu16.04-x64 with jdk9.0.4b07-64bit,the results:failed as the same issue)
(Test on ubuntu16.04-x64 with jdk10.0.1b07-64bit,the results:failed as the same issue)
[If Regression] Regression introduced in release/build:
Test result on the last GAed release for this train:Failed(test with jdk9b181-64bit on Ubuntu16.04-x64)
[if Fail] Test result on FCS:

Is it a platform specific issue:NO
(Test on Mac10.11-x64 with jdk9b181-64bit,the results:failed as the same issue)
(Test on win10-x64 with jdk9b181-64bit,the results:failed as the same issue)
[If platform specific issue] Is it a new (previously unsupported) OS/browser/mode testing:
[If new configuration testing] Issue specific to execution mode or OS/browser version:

Steps to reproduce:
1. Install Test build JDK9b126 (64bit) and set JAVA_HOME env
2. use test bundle:java-client-9-manual-new.tar.gz and extract to a folder of java-client-9-manual <WS>
3. Install ANT (version:1.9.7) and set ANT_HOME env
4. Change javafx.home path in build.properties file(under the folder <WS>)
5 Enter the testsuite "JavaFXCompatibility" directory(under the folder<WS>) and run command: ant run-manual
6. Run the case: graphics/api/control/treeview/TreeViewTest08Test.java in the harness.

Instructions:
TreeView must be displayed with no selection,it should show as the reference image.

Actual result:
Once the app loaded, text "Selected: null" will not show, please refer to attachment.