Why are we experiencing intermittent exceptions while running Multi JVM tests?

We are currently experiencing the following issue while running our Multi JVM test:
java.util.ConcurrentModificationException: Two threads have apparently attempted to run a suite at the same time. This has resulted in both threads attempting to concurrently change the current Informer.

This crashes one of the JVMs causing the test to fail.

The test is run as part of our CI pipeline and this issue happens regularly but sporadically.

This is the only MultiJVM test we have in our codebase.

Anyone experienced the same or have any insight into why this is happening?