AMD Answer 72881
Under a combination of conditions, a younger load re-using the same group identifier (GID) as an older device load might report a synchronous external abort by improperly associating an external error detected by an older device memory access. Device loads resolve early and allow subsequent instruction execution to re-use the GID.
This is a third-party errata (Arm, Inc. 1537003); this issue will not be fixed.