Two tests running on the same host as part of the same test run:

Test: com/sun/jdi/JdwpNetProps.java

Debuggee is listening on localhost:48273
Connecting from 0:0:0:0:0:0:0:1, expected: Failure
----------System.err:(12/704)----------
java.lang.RuntimeException: ERROR: attached successfully
at JdwpNetProps$ListenTest.run(JdwpNetProps.java:140)
at JdwpNetProps.main(JdwpNetProps.java:79)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.VirtualThread.run(VirtualThread.java:309)

Test: com/sun/jdi/JdwpListenTest.java

[debuggee] Listening for transport dt_socket at address: 48273
[debuggee] Listening for transport dt_socket at address: 57147
Debuggee is listening on 0:0:0:0:0:0:0:1%1:48273
Connecting to 0:0:0:0:0:0:0:1%lo, expected: SUCCESS
----------System.err:(24/1468)----------
java.lang.RuntimeException: ERROR: failed to attach
at JdwpListenTest.listenTest(JdwpListenTest.java:106)
at JdwpListenTest.main(JdwpListenTest.java:67)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.VirtualThread.run(VirtualThread.java:309)
Caused by: java.net.ConnectException: Connection refused
at java.base/sun.nio.ch.Net.pollConnect(Native Method)
at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:682)
at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:598)
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327)
at java.base/java.net.Socket.connect(Socket.java:751)
at jdk.jdi/com.sun.tools.jdi.SocketTransportService.attach(SocketTransportService.java:263)
at jdk.jdi/com.sun.tools.jdi.GenericAttachingConnector.attach(GenericAttachingConnector.java:119)
at jdk.jdi/com.sun.tools.jdi.SocketAttachingConnector.attach(SocketAttachingConnector.java:83)
at JdwpListenTest.attach(JdwpListenTest.java:125)
at JdwpListenTest.listenTest(JdwpListenTest.java:99)
... 5 more

Very similar to JDK-8231915