I just ran into this issue as well. I have the premier model and was able to connect with an expert reviewer. Thank you for posting this question because I referenced this post and it expedited my help. They immediately reached out to the tech team.
Basically, they said the IRS's current e-file system does not process federal refund amount changes. Any federal refund amounts changes will be automatically rejected. It is a bug on the IRS e-file system.
The solution provided: Opt to print your amendment forms and mail it in. Make sure to go to the post office to send via certified mail (tracking).
