Thank you for the comments and time posting.
I’ve troubleshooted this in various detail since posting but unable to find a quick fix. The workaround was to reinstall Windows on the desktop systems and deploy new images for the VMs (attaching the VMDK files).
Fortunately, this issue only affected a handful of systems (in a large organisation) and we have not seen the occur since, so will focus on new issues.
Appreciate your help.
