Problematic tests list (32 rows):
bugs.core_0972_test  Case insensitive collation for UTF-8
bugs.core_1760_test  Support hex numeric and string literals
bugs.core_2581_test  Infinity should not escape from the engine (client side tools should not see the special values)
bugs.core_4754_test  Bugcheck 167 (invalid SEND request) while working with GTT from several attachments (using EXECUTE STATEMENT ... ON EXTERNAL and different roles)
bugs.core_5275_test  Expression index may become inconsistent if CREATE INDEX was interrupted after b-tree creation but before commiting
bugs.core_5481_test  Available indices are not used in some cases if ORDER BY expression is a filtered one
bugs.core_5488_session_idle_test  Timeouts for running SQL statements and idle connections
bugs.core_5921_test  Provide information about Global Commit Number, Commit Number of currently used database snapshot (if any) and Commit Numbers assigned to the committed transactions
bugs.core_6095_test  Extend trace record for COMMIT/ROLLBACK RETAINING to allow chaining of transaction ids
bugs.core_6444_test  Ability to query Firebird configuration using SQL
bugs.gh_0310_test  System table with keywords
bugs.gh_6809_test  Integer hex-literals: support for INT128
bugs.gh_7050_test  Add table MON$COMPILED_STATEMENTS and columns
bugs.gh_7398_test  Worst plan sort created to execute an indexed tables
bugs.gh_7466_plans_tracking_test  Add COMPILE trace events - ability to see execution plan of every PSQL statement.
bugs.gh_7466_test  Add COMPILE trace events for procedures/functions/triggers
bugs.gh_7804_test  The partial index is not involved when filtering conditions through OR.
bugs.gh_7904_test  More realistic cardinality adjustments for unmatchable booleans // FB5 bad plan for query
bugs.gh_8077_test  Error "Too many recursion levels" does not stop execuition of code that uses ON DISCONNECT trigger (FB 4.x+)
bugs.gh_8161_test  Cardinality estimation should use primary record versions only
bugs.gh_8278_test  Avoid index lookup for a NULL key if the condition is known to always be FALSE in this case
bugs.gh_8851_test  'Internal error' when calling outer procedure after deleting unused result variable from inner procedure
bugs.gh_9192_test  ORDER BY in window function causes slowdown because the frame is evaluated for every row ...
functional.arno.optimizer.test_opt_inner_join_05  INNER JOIN join order LIKE and STARTING WITH
functional.dtt.test_dtt_max_count  DECLARED TEMPORARY TABLE - check max limit for DTT that can be created within each kind of PSQL unit.
functional.gtcs.test_cast_datatypes  Check result or CAST() for misc agruments // from GTCS.
functional.ltt.test_ltt_savepoints_2  LTT. Regression with SAVEPOINTS.
functional.metacache.test_95996928  Avoid infinite wait due to non-optimum plan & use of read committed no record version transaction for DML by ISQL
functional.sqlite.test_b383b90278  Assertion in UPDATE statement for textual column which has check constraint that involves numeric comparison
functional.table.alter.test_05  ALTER TABLE - ALTER - TO
functional.trigger.alter.test_alter_dml_basic  ALTER TRIGGER - basic checks for DML triggers
functional.trigger.database.test_transactioncommit_01  Trigger on commit transaction. See also CORE-645

This list is the same for:
6.0.0.2211 2026.10.14 1a432d5c  CS