FrameDemoTest fails randomly while doing state changes

FrameDemoTest changes frame state from NORMAL-> MAXIMIZED_BOTH-> NORMAL-> ICONIFIED-> NORMAL.
Also then it moves and resizes the same frame.
While executing this test in SBR setup, we are seeing random failures on state change.
Attached some of the logs and screenchots under Error_Logs_Screenshots.zip.
Issue observed in Linux and Osx platform.

Steps to reproduce:
Download and unzip TestCase.zip
Copy FrameDemoTest.java to folder /test/jdk/sanity/client/SwingSet/src
Copy 'frame' folder under test/jdk/sanity/client/lib/SwingSet3/src/com/sun/swingset3/demos

Run these tests iteratively, say 1000 iterations.

Command to execute:
./jtreg/bin/jtreg -verbose:all -jdk:./testjdk/jdk-12 -dir:./testbase/12/jdk/test sanity/client/SwingSet/src