I've got 2 t2.large instances which need to be upgrade to t2.xlarge. Problem is that t2.* is not available in the change type drop-list!
I created another instance - like the first one - , I can update to t2.xlarge. I added 2 EBS disk - like the first one -, I can update to t2.xlarge.
Any idea of what can limits the list of available type of instance in the drop-list?!
It was a placement group configuration issue!
https://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/general-purpose-instances.html?shortFooter=true#general-purpose-features