It seems the fix for JDK-8356114 is insufficient to address the timeout issue.
The test failed again:

----------System.err:(1/91)----------
STARTED TestBufferStackStress2::movingVirtualThreadWithGc 'movingVirtualThreadWithGc()'
----------System.out:(3/131)----------
VT: 0:496200293 ALLOCATING = VirtualThread[#15]/runnable
PT: 1:773791952 FJP HAS CONTRACTED
PT: 1:774207147 CLOSING EXECUTOR
result: Error. "junit" action timed out with a timeout of 480 seconds on agent 9


test result: Error. "junit" action timed out with a timeout of 480 seconds on agent 9