So you mean even if the people registered under the same IP address submit their KYC, it will still be considered as multiple accounts? What if we inform the casino team itself about this situation?
You are supposed to be an active member of this forum, especially on the gambling board, so I assume you are familiar with this term which you can read on the terms of service of many casinos that are promoting their services here “one player per household".
So yes, if multiple accounts share the same IP address then you can not blame the casino for tagging them as alt accounts. Even if they are not, based on the terms of service, they are still violating the rules of the casino.