On the podcast Pod Save America, an Obama aide claimed that the appointment of Steve Bannon to the National Security Council was a mistake. They said Trump was upset because he found out Bannon was on the council, insinuating (rather explicitly) that the president was signing stuff and not really paying attention. I have found no evidence of this anywhere, is this just a rumor?
The original source for the claim seems to be the New York Times:
[F]or the moment, Mr. Bannon remains the president’s dominant adviser, despite Mr. Trump’s anger that he was not fully briefed on details of the executive order he signed giving his chief strategist a seat on the National Security Council, a greater source of frustration to the president than the fallout from the travel ban.
The report seems to be based on insider information, and obviously doesn't name those sources.