It needs investigating and not only because of this anomaly happening twice.
Surprise, surprise, it has been investigated by it's opponents and it's been proven to be full of unproven accusations.
Not to suggest that the election wasn't stolen from Trump, because I would be happier to see that claim being upheld.
The very meaning of fascism taking down a democracy:
The election was stolen.
or
The belief in the minds of the people that the election was stolen. (which negates the ability of the DOJ to arrest the leader of an attempted coup)