While investigating the failures at https://github.com/infinispan/infinispan/pull/10153 it was found that when restarting the cache with SIFS and deleting the old index it is possible that an old replaced value was resurrected on accident. The test added has a line commented out that reproduces the issue every time.

~_{It appears to be something with the old sequence id check when a file with a lower number has an old value.}~

Upon further investigation the code is working properly, the test was changed to not insert a different key on every iteration, so the assertion needed to be updated to reflect that.