SQl tuning advisor / SQL skipped due to errors

Hi all,

the results of  my Automatic SQL Tuning (SYS_AUTO_SQL_TUNING_TASK) show a number of SQL "skipped due to errors". Drilldown into recommendations shows "Error ORA-00942: table or view does not exist" for a specific SQL (and also for some others).

However, when I create a SQL tuning advisor task for that SQL, I get valid recommendations.

Some analysis shows that the SQL was executed successfully with parsing schema name present:

select count(*), min(snap_id), max(snap_id), sql_id, parsing_schema_name, plan_hash_value from dba_hist_sqlstat
where sql_id ='d8vnpvq0t3bn9'