And it appears they have the authority to do just that:
The House Democratic investigations could pave the way for a new election in the district, even if the court orders the board of elections to certify Harris as the winner instead of the board ordering a re-vote itself. The House Administration Committee, now controlled by Democrats, has the authority to call for another election after investigating the 2018 results.
Rep. Marcia Fudge (D-Ohio), who is slated to chair an election-focused subcommittee of the House Administration Committee, told POLITICO that the House will intervene if the North Carolina court ordered the election certified for Harris before the state investigation has concluded. Any House member could object to seating Harris and block him, triggering an investigation by Fudge's committee.
It might seem like a trivial detail, but you'll notice from the headline above I didn't say, "...court tries to certify Harris." Because it does not have that authority. It does, however, have the authority to "direct" the NC BoE to certify Harris, via Writ of Mandamus. But Congress itself has the final say, apparently: