Abaqus - Older simulations run in Abaqus 2021 not reproducing same results

I have a set of simulations and umat/vumats which were created on version 6.14 by a colleague a few years ago. When I run those simulations now on newer version of Abaqus (2021) the results are completely off. These are high velocity dynamic simulations run in Dynamic Explicit. Have there been substantial changes between the two versions to justify this?