in the recent past we are getting more and more issues with parallel steps in scripted pipeline which seems fail more or less randomly with java.io.NotSerializableException: groovy.lang.IntRange although we do not use ranges in the pipeline code and the stacktraces also do not contain any custom code entries. I am not sure that the issue is related to the parallel step but it seems to only happen during execution of parallel step branches.
This issue started occurring without any change to the pipeline code. At first the error happened once in a while but it's starting to get more and more frequent where e.g. a job with many parallel steps that runs nightly almost always fails nowadays.