@spikhalskiy @tihomir I managed to make a sample that reproduces the issue. The repository is absolutely hideous, but it’s all I had time for: GitHub - neshield/temporal-break-replay-history
See the README.md instructions: In intelliJ, select run all the test in the "retries" directory. It should fail around 5% of the time. I tried removing some of the tests in the retries directory, but it either prevented the issue from appearing, or made it happen less frequently. So, the best I could do is the set of 4 tests that need to be run over and over until they eventually fail.