javax/net/ssl/DTLS/WeakCipherSuite.java failed with timeout. I attached jtr and process information to the bug.
Please refer to parts of jstack output below:
"Attach Listener" #16 daemon prio=9 os_prio=31 tid=0x00007fa385863000 nid=0x550b waiting on condition [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

"pool-1-thread-2" #15 prio=5 os_prio=31 tid=0x00007fa382840000 nid=0x7b03 runnable [0x000000012426a000]
   java.lang.Thread.State: RUNNABLE
at java.net.PlainDatagramSocketImpl.receive0(java.base@10-internal/Native Method)
- locked <0x00000007a0113000> (a java.net.PlainDatagramSocketImpl)
at java.net.AbstractPlainDatagramSocketImpl.receive(java.base@10-internal/AbstractPlainDatagramSocketImpl.java:180)
- locked <0x00000007a0113000> (a java.net.PlainDatagramSocketImpl)
at java.net.DatagramSocket.receive(java.base@10-internal/DatagramSocket.java:814)
- locked <0x00000007a084ae60> (a java.net.DatagramPacket)
- locked <0x00000007a0112fc0> (a java.net.DatagramSocket)
at DTLSOverDatagram.handshake(DTLSOverDatagram.java:171)
at DTLSOverDatagram.doClientSide(DTLSOverDatagram.java:117)
at DTLSOverDatagram$ClientCallable.call(DTLSOverDatagram.java:685)
at DTLSOverDatagram$ClientCallable.call(DTLSOverDatagram.java:668)
at java.util.concurrent.FutureTask.run(java.base@10-internal/FutureTask.java:264)
at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@10-internal/ThreadPoolExecutor.java:1161)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@10-internal/ThreadPoolExecutor.java:635)
at java.lang.Thread.run(java.base@10-internal/Thread.java:844)

"pool-1-thread-1" #14 prio=5 os_prio=31 tid=0x00007fa38283f000 nid=0x7a07 runnable [0x0000000124167000]
   java.lang.Thread.State: RUNNABLE
at java.net.PlainDatagramSocketImpl.receive0(java.base@10-internal/Native Method)
- locked <0x00000007a0160eb8> (a java.net.PlainDatagramSocketImpl)
at java.net.AbstractPlainDatagramSocketImpl.receive(java.base@10-internal/AbstractPlainDatagramSocketImpl.java:180)
- locked <0x00000007a0160eb8> (a java.net.PlainDatagramSocketImpl)
at java.net.DatagramSocket.receive(java.base@10-internal/DatagramSocket.java:814)
- locked <0x00000007a082b3b8> (a java.net.DatagramPacket)
- locked <0x00000007a015ca28> (a java.net.DatagramSocket)
at DTLSOverDatagram.handshake(DTLSOverDatagram.java:171)
at DTLSOverDatagram.doServerSide(DTLSOverDatagram.java:98)
at DTLSOverDatagram$ServerCallable.call(DTLSOverDatagram.java:647)
at DTLSOverDatagram$ServerCallable.call(DTLSOverDatagram.java:630)
at java.util.concurrent.FutureTask.run(java.base@10-internal/FutureTask.java:264)
at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@10-internal/ThreadPoolExecutor.java:1161)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@10-internal/ThreadPoolExecutor.java:635)
at java.lang.Thread.run(java.base@10-internal/Thread.java:844)

"MainThread" #13 prio=5 os_prio=31 tid=0x00007fa386004000 nid=0x7203 waiting on condition [0x0000000124064000]
   java.lang.Thread.State: WAITING (parking)
at jdk.internal.misc.Unsafe.park(java.base@10-internal/Native Method)
- parking to wait for <0x00000007a01160d0> (a java.util.concurrent.FutureTask)
at java.util.concurrent.locks.LockSupport.park(java.base@10-internal/LockSupport.java:194)
at java.util.concurrent.FutureTask.awaitDone(java.base@10-internal/FutureTask.java:447)
at java.util.concurrent.FutureTask.get(java.base@10-internal/FutureTask.java:190)
at DTLSOverDatagram.runTest(DTLSOverDatagram.java:606)
at WeakCipherSuite.main(WeakCipherSuite.java:60)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(java.base@10-internal/Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(java.base@10-internal/NativeMethodAccessorImpl.java:62)
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(java.base@10-internal/DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(java.base@10-internal/Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.lang.Thread.run(java.base@10-internal/Thread.java:844)

"Service Thread" #11 daemon prio=9 os_prio=31 tid=0x00007fa38501f800 nid=0x6e03 runnable [0x0000000000000000]
   java.lang.Thread.State: RUNNABLE

"Common-Cleaner" #10 daemon prio=8 os_prio=31 tid=0x00007fa38485e000 nid=0x6c03 in Object.wait() [0x0000000123d5b000]
   java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(java.base@10-internal/Native Method)
- waiting on <0x00000007a0252f98> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(java.base@10-internal/ReferenceQueue.java:151)
- waiting to re-lock in wait() <0x00000007a0252f98> (a java.lang.ref.ReferenceQueue$Lock)
at jdk.internal.ref.CleanerImpl.run(java.base@10-internal/CleanerImpl.java:148)
at java.lang.Thread.run(java.base@10-internal/Thread.java:844)
at jdk.internal.misc.InnocuousThread.run(java.base@10-internal/InnocuousThread.java:122)


There is more detail in attached processes.html.