We just managed to do a deployment as well and it worked.
Do you have any indication as to what caused the issue in the backend? My assumption is that the IAM user for the service got deleted before the service deployment successfully finished and this caused the issue?
Indeed, your assumption is good, as explained above:
Itās likely the update failed somewhere after old user for iam-eks-user-mapper got deleted and before new iam-eks-user-mapper app version got deployed. It should not happen, I will investigate on our end and patch if I find anything which may leads to this situation.