We had indeed a bug on our end, preventing terraform to be in a good state in some use cases.
The issue has been addressed and a patch has been released on our end.
I triggered an update on your cluster, these error is gone, but you are hitting a vCPU AWS quotas on your side: VcpuLimitExceeded - You have requested more vCPU capacity than your current vCPU limit of 32 allows for the instance bucket that the specified instance type belongs to.