"On Monday, the FTC requested more information from both companies about the $1.7 billion deal, according to an investor filing from iRobot, in what’s known as a “second request” and an indicator of deeper scrutiny by antitrust officials."
There are later press communications where Khan's FTC took credit for it. There was a strong implication they let the EU do the lifting but would have filed suit if they hadn't.
So, that is common and doesn't mean they are going to shut down a deal. E.g., also in 2022 they made a "second request" for the Broadcom acquisition of VMWare and that one went through.
