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