Apparently the same issue occurred the night before with the incoming jet having to do a go around..

https://www.washingtonpost.com/dc-md...DIOF26EZA2N5H4

"On Tuesday night, just 24 hours before a deadly collision between a military helicopter and a regional jet over the Potomac River near Reagan National Airport, a different regional jet coming in for a landing at the airport alerted the air traffic control tower that it had to make a second approach.

The cockpit crew quickly reported the reason to the tower: A helicopter had appeared near the flight path."