As been in BF-38360, a catalog cache refresh of the "config.system.sessions" can cause problem with the session visibility when running $listLocalSessions direct after startSession command. Wrap the $listLocalSession assertions in an assert.soon or run refreshLogicalSessionCacheNow before the command to make it more robust to transient issues. 

-It looks like the issue is actually that this test is not compatible with cache refreshes, as it has already been tagged with does_not_support_config_fuzzer to avoid that. However, from the two BFGs, it looks like potentially the CheckMetadataConsistencyInBackground thread (or something else) is causing a cache refresh to happen. -

Repurposing this ticket to try to add logging to help debug this if it happens again