Since 6th February we see those tests failing when testing with the product builds; failure shows up only on macOS aarch (on one of our test machines with this setup : "Macmini9,1" arm64, 8 cores, 16G, Darwin 20.6.0, macOS 11.6.1 ).
Failing tests :

gc/stringdedup/TestStringDeduplicationAgeThreshold.java#Serial
gc/stringdedup/TestStringDeduplicationFullGC.java#Serial
gc/stringdedup/TestStringDeduplicationInterned.java#Serial
gc/stringdedup/TestStringDeduplicationPrintOptions.java#Serial
gc/stringdedup/TestStringDeduplicationTableResize.java#Serial
gc/stringdedup/TestStringDeduplicationYoungGC.java#Serial

for example gc/stringdedup/TestStringDeduplicationAgeThreshold.java#Serial

# Internal Error (cardTableRS.cpp:122), pid=6292, tid=13827
# guarantee(_card_table->is_dirty_for_addr(obj)) failed: Found unmarked old-to-young pointer
#

Stack: [0x000000016b880000,0x000000016ba83000], sp=0x000000016ba81f70, free space=2055k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0xa8ffcc] VMError::report_and_die(int, char const*, char const*, char*, Thread*, unsigned char*, void*, void*, char const*, int, unsigned long)+0x554 (cardTableRS.cpp:122)
V [libjvm.dylib+0xa90788] VMError::report_and_die(Thread*, unsigned int, unsigned char*, void*, void*)+0x0
V [libjvm.dylib+0x2fcdf0] print_error_for_unit_test(char const*, char const*, char*)+0x0
V [libjvm.dylib+0x213bb8] CheckForUnmarkedOops::do_oop(oopDesc**)+0x0
V [libjvm.dylib+0x96a56c] ContiguousSpace::object_iterate(ObjectClosure*)+0x98
V [libjvm.dylib+0x213970] CardTableRS::verify()+0x38
V [libjvm.dylib+0xa40838] Universe::verify(VerifyOption, char const*)+0x1e0
V [libjvm.dylib+0x8e3f88] SerialHeap::collect_generation(Generation*, bool, unsigned long, bool, bool, bool)+0x2c4
V [libjvm.dylib+0x8e443c] SerialHeap::do_collection(bool, bool, unsigned long, bool, SerialHeap::GenerationType)+0x3c8
V [libjvm.dylib+0x8e4c88] SerialHeap::satisfy_failed_allocation(unsigned long, bool)+0x110
V [libjvm.dylib+0x8e6898] VM_GenCollectForAllocation::doit()+0x54
V [libjvm.dylib+0xa96c5c] VM_Operation::evaluate()+0xe8
V [libjvm.dylib+0xaa72e8] VMThread::evaluate_operation(VM_Operation*)+0xc4
V [libjvm.dylib+0xaa7bd4] VMThread::inner_execute(VM_Operation*)+0x29c
V [libjvm.dylib+0xaa6fdc] VMThread::run()+0xd0
V [libjvm.dylib+0xa11d94] Thread::call_run()+0xc8
V [libjvm.dylib+0x84b4f8] thread_native_entry(Thread*)+0x118
C [libsystem_pthread.dylib+0x7878] _pthread_start+0x140
VM_Operation (0x000000016b66a4f0): GenCollectForAllocation, mode: safepoint, requested by thread 0x000000013a008600