Problematic tests list (63 rows):
bugs.core_0883_test  The built-in BLR printer doesn't support all FB2 features
bugs.core_1152_test  Cannot erase a table with check constraints referencing more than a single columns
bugs.core_3690_dialect_3_test  Wrong warning message for ambiguous query
bugs.core_4302_addi_test  Lookup (or scan) in descending index could be very inefficient for some keys
bugs.core_4302_test  Lookup (or scan) in descending index could be very inefficient for some keys
bugs.core_4337_test  gfix -sweep makes "reconnect" when it is removed from mon$attachments by delete command (issued in another window)
bugs.core_4731_test  Prohibit an ability to issue DML or DDL statements on RDB$ tables (CORE-4731)
bugs.core_4819_test  EXECUTE PROCEDURE's RETURNING_VALUES and EXECUTE STATEMENT's INTO does not check validity of assignments targets leading to bugcheck
bugs.core_4880_test  Better performance of creating packages containing many functions
bugs.core_4937_test  View/subselect with "union" does not use computed index
bugs.core_5383_test  Dependencies in Package not recognised
bugs.core_5410_test  Dependencies are not stored when using some type of contructions in subroutines
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_5606_test  Add expression index name to exception message if computation failed
bugs.core_5618_test  Part of the pages of the second level blobs is not released when deleting relations
bugs.core_5737_test  Invalid parameters of gds transaction in ISQL
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_6166_test  Problems with long object names (> 255 bytes)
bugs.core_6300_test  Next attachment id, next statement id and some other additions [CORE-6300]
bugs.core_6444_test  Ability to query Firebird configuration using SQL
bugs.gh_0310_test  System table with keywords
bugs.gh_6785_test  Problem when restoring the database on FB 4.0 RC1 (gbak regression)
bugs.gh_6869_test  Domain CHECK-expression can be ignored when we DROP objects that are involved in it
bugs.gh_7050_test  Add table MON$COMPILED_STATEMENTS and columns
bugs.gh_7141_test  Services manager breaks long lines into 1023 bytes portions when using isc_info_svc_line in Service::query()
bugs.gh_7220_test  Dependencies of subroutines are not preserved after backup restore
bugs.gh_7304_test  Events in system attachments (like garbage collector) are not traced
bugs.gh_7398_test  Worst plan sort created to execute an indexed tables
bugs.gh_7426_test  Ensure the DDL trigger requests are cached
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_8219_test  Database creation in 3.0.12, 4.0.5 and 5.0.1 slower than in previous releases
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_8661_test  Strange output from SHOW DEPENDENCIES command on 6.0
bugs.gh_8663_test  Problem with restore time when DB has many indices (possible regression in 6.x)
bugs.gh_8851_test  'Internal error' when calling outer procedure after deleting unused result variable from inner procedure
functional.arno.optimizer.test_opt_inner_join_05  INNER JOIN join order LIKE and STARTING WITH
functional.basic.isql.test_02  ISQL - SHOW SYSTEM TABLES
functional.basic.isql.test_03  ISQL - SHOW SYSTEM parameters
functional.blob.test_blob_over_4gb  Check ability to operate with blob with size greater than 4Gb
functional.gtcs.test_computed_fields_13  Computed fields
functional.gtcs.test_misplaced_collation_in_extracted_metadata  Misplaced collation when extracting metadata with isql
functional.gtcs.test_returning_01  Test of RETURNING clause: INSERT, UPDATE, MERGE.
functional.replication.test_ddl_triggers_must_not_fire_on_replica  DDL-triggers must fire only on master DB
functional.replication.test_disallow_rdb_backup_history_replication  Disallow replication of RDB$BACKUP_HISTORY
functional.replication.test_duplicates_in_rw_replica_after_conflicting_insert  Conflicting INSERT propagated into a read-write replica may cause duplicate records to appear
functional.replication.test_failed_ddl_commands_can_be_replicated  Failed DDL commands can be replicated
functional.replication.test_generator_could_not_be_transferred_to_replica  Generator values may not replicate after commit
functional.replication.test_invalid_msg_if_target_db_has_no_replica_flag  Invalid message in replication.log (and possibly crash in the case of synchronous replication) when the target DB has no its "replica" flag set
functional.replication.test_lookup_problems_for_intl_data_in_unique_indices  Lookup problems for INTL strings in unique indices
functional.replication.test_make_async_reinit_reliable  Make asynchronous replica re-initialization reliable #8324
functional.replication.test_shutdown_during_applying_segments_leads_to_crash  Crash or hang while shutting down the replica database if segments are being applied
functional.replication.test_some_updates_crash_server_on_replica_side  Some updates can crash Firebird server on replica side
functional.replication.test_sync_replica_allow_spaces_in_username_or_password  Leading, trailing or inner space character specified in 'sync_replica' must not cause error
functional.replication.test_sync_replica_server_hangs_on_disconnect  Synchronous replication hangs on disconnect [CORE6497]
functional.replication.test_uk_violation_in_rw_repl_if_constraint_name_is_used  PK/UK violation error raises in RW replica if constraint name is used to check uniqueness instead of index name
functional.replication.test_updating_blob_with_empty_string_stops_replication  Replication gets stuck due to "Blob xxx.xx is not found for table xxx" error

This list is the same for:
6.0.0.1948 2026.05.13 f8eee951  SS