Problematic tests list (11 rows):
bugs.core_0733_test  Compress Data over the Network
bugs.core_1263_test  GSec incorrectly processes some switches
bugs.core_5501_test  Unclear gstat's diagnostic when damaged page in DB file appears encrypted
bugs.gh_8263_test  gbak on Classic with ParallelWorkers > 1 doesn't restore indices, giving a cryptic error message
bugs.gh_8386_test  Crash when creating index on table that uses UDR and ParallelWorkers > 1
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

This list is the same for:
5.0.3.1648 2025.04.18 2f4c51ec  CS
5.0.3.1649 2025.04.21 5b2d0dcc  CS
5.0.3.1650 2025.04.28 4cbff060  CS
5.0.3.1651 2025.04.30 141ef4cc  CS
5.0.3.1652 2025.05.13 f51c6e65  CS