Problematic tests list (15 rows):
bugs.core_2650_test  Improve sorting performance when long VARCHARs are involved
bugs.core_5501_test  Unclear gstat's diagnostic when damaged page in DB file appears encrypted
bugs.gh_8109_test  Plan/Performance regression when using special construct for IN in FB5.x compared to FB3.x
bugs.gh_8185_test  SIGSEGV in Firebird 5.0.0.1306 embedded during update on cursor
bugs.gh_8263_test  gbak on Classic with ParallelWorkers > 1 doesn't restore indices, giving a cryptic error message
bugs.gh_8356_test  Make Trace use HEX representation for parameter values of types [VAR]CHAR CHARACTER SET OCTETS and [VAR]BINARY
bugs.gh_8386_test  Crash when creating index on table that uses UDR and ParallelWorkers > 1
bugs.gh_8394_test  Make Trace use HEX representation for parameter values of types [VAR]CHAR CHARACTER SET OCTETS and [VAR]BINARY
functional.arno.optimizer.test_opt_sort_by_index_10  ORDER BY ASC using index (multi)
functional.arno.optimizer.test_opt_sort_by_index_13  ORDER BY ASC using index (multi)
functional.arno.optimizer.test_opt_sort_by_index_19  ORDER BY ASC using index (multi) and WHERE clause
functional.basic.isql.test_02  ISQL - SHOW SYSTEM TABLES
functional.replication.test_make_async_reinit_reliable  Make asynchronous replica re-initialization reliable #8324
functional.tabloid.test_333be4bf  Change error by warning in the case when isc_dpb_parallel_workers value is not at valid range
functional.tabloid.test_e260ced8  Allow computable but non-invariant lists to be used for index lookup

This list is the same for:
5.0.2.1577 2024.12.24 3c80e7c5  CS
5.0.2.1577 2025.02.07 f50a2860  CS