Is this even legal? Biden fires Senate appointed NLRB Lawyer

Biden fires Senate appointed NLRB Lawyer. Is this even legal? Now this was a Senate approved appointee for a four year position. He has 10 months left. Peter Robb, who was appointed to the position by former President Trump and confirmed to the four-year position, was notified by the Biden administration Wednesday afternoon that he needed to resign or he would be fired, Bloomberg Law first reported. 

The NLRB is an independent federal agency that enforces collective bargaining laws and manages union-business disputes, according to the Huffington Post.  Members of Congress are already condemning this action. What say you?