There is a !PRODUCT vs ASSERT mismatch for CollectedHeap::check_for_non_bad_heap_word_value. The definition is !PRODUCT, but the filling is debug-only (see SpaceMangler::mangle_region). This means the function will fail in "optimized" builds. This filling and checking is inappropriate for an "optimized" build, and this should all be debug-only.

see: https://mail.openjdk.java.net/pipermail/hotspot-dev/2019-October/039804.html