As a workaround, set the parameter _aq_tm_scanlimit = 0 to disable automatic coalesce of AQ IOTs.
1) --Disable auto coalesce by setting _aq_tm_scanlimit to 0
ALTER SYSTEM SET "_aq_tm_scanlimit"=0 SCOPE=BOTH SID='*';
2) Run flush, twice:
alter system flush buffer_cache;
alter system flush buffer_cache;
3) Stop and restart qmon
ALTER SYSTEM SET aq_tm_processes=0 SCOPE=MEMORY;
-- wait until no rows are returned that show QMNC or Q00x
select PID , spid, pname from v$process where pname like 'Q%';
--Then set to 1
ALTER SYSTEM SET aq_tm_processes=1 SCOPE=MEMORY;