fsm_workload_helpers/kill_session.js's killSession function begins by refreshing the logical session cache, expecting that this command may fail during certain circumstances. However, it is also possible that this command will fail with NoProgressMade (and possibly other errors) if the writes to the session collection are killed by another session killer during the refresh (see this comment on BF-25968).

killSession should either consider additional error codes to be acceptable, or perhaps retry at least once in case of an error.