BF-23386 is caused by IndexBuildAborted errors being thrown during the createIndexes command in find_flip_sbe_enabled.js.
Looking at SERVER-45988, it seems that it's now possible for createIndexes in FSM tests to get an IndexBuildAborted error if an index is concurrently being dropped, instead of an IndexBuildAlreadyInProgress error, which is what would have been thrown in the past, and is an error that we already ignore.
I also noticed that many of the other fsm tests ignore this error. As a result of these observations, even though after many attempts I have not been able to reproduce it locally, I believe it's safe to ignore this error.