Random error - Failed to find reply channel for message correlation key

**Citrus Version**
3.1.2

**Question**
When running tests in parallel the following error happens, sometimes:
FAILURE: Caused by: TestCaseFailedException: Failed to find reply channel for message correlation key: citrus_message_id = '684ca45c-854f-4dc6-a0b6-940e6fa93460'

How can this error be avoided? Thanks!

**What I've tried so far**
Ensured that all test methods of the test classes in the group have the following paremeters, as per the user guide:
@Optional @CitrusResource TestCaseRunner runner
@Optional @CitrusResource TestContext context

**Additional information**
This error occures only on one of the HttpServer endpoints. The tests use other HttpServer endpoints too.
The test methods have the following kind of annotations (sample):
@CitrusTest
@Test(groups = {"g1", "g2"})
Tests are run like this:
mvn clean install -Dgroups=g1 -DthreadCount=2 -Dparallel=methods
The pom.xml has the citrus-testng reference for test execution

Start by reproducing the failure with the reported Maven command, TestNG method parallelism, two threads, and the affected HttpServer endpoint. Trace the reply-channel lookup for the reported message correlation key and compare it with the endpoints that do not fail; done means parallel tests complete without the intermittent error.

Written by the indexing model from the issue text.