"I did not file early only two weeks ago"

Lacerte, Proseries, ProConnect, and even TurboTax are just being updated yesterday and today. That will cover the UI issue. I don't know if it also covers the APTC issue.

You know Congress passed retroactive changes. The IRS announced not to file amended returns, because they would "do the math" on returns already filed.

"Early" from the perspective of the programs in use here. Not "early" from the perspective of the filing due date, which you also know has been moved out to May 17.

So, "how is this possible?" IRS has the right to make any change they deem necessary. Have you or your client logged into their "where's my refund" to see any any messaging that might be there?