[ANSI JOINS] sometimes this query hangs and sometimes it runs fine

Hello so I have this VM setup: http://172.23.105.209:8091/

There is basically a primary index on both tables and a secondary index on the int_field1 of multiple table_db_1595_simple_table_10. 

Basically with the environment how it is right now this query:

select * from (select int_field1 from multiple_table_db_1595_simple_table_1 WHERE (select bool_field1 from multiple_table_db_1595_simple_table_1 t10 WHERE bool_field1 = false)) t1 JOIN multiple_table_db_1595_simple_table_10 t2 ON t1.int_field1 = t2.int_field1

will sometimes execute just fine and produce 101 results, but sometimes (rarely) It will hang (at least me watching it for >5 mins it doesn't produce results). 

It is currently running the query in the QWB as we speak (query started at ~3:57 PM PST). I have left it running in the QWB in case you want to inspect it right now. As of 3:59 PM PST this query is still trying to execute.