I've noticed in some recent and old threads about players having issues with sportsbooks/casinos holding back, denying, or reducing payouts due to the fact that the player also has an account with a sister site(s). 5 Dimes has a sister site Sportbet, for example.
I would suggest (if it hasn't already been) that the SBR review of each sportbook also list the sister site (if any) for the player's information. The 5 Dimes review doesn't mention the Sportbet site.
What are the main concerns the sportsbooks have about a player having an account at a sister site?