@sweeperjbf you can look to the thread below for additional info on one owner running multiple teams, but sometimes it’s easier to just talk to the owners in question privately to understand if there’s any relationship between them that might be good for the league to know.
Suspicious transactions and shared leagues shouldn’t be enough to make these accusations, but if you have concerns, I’d recommend just working through your commissioner to talk those teams, rather than opening some form of investigation from Niv on them, but yeah if all else fails you can e-mail for support.