What I stumble upon is about they say "they recognized my betting pattern (betting on same sports and same casino games like my first account)." I just barely know that the site or casino is able to detect pattern

that just insane frenn.
You said that you are use 2 different account with 2 different id with 2 different laptop but they still know about it just marvelous in my opinion. Are they using AI or some sort
He could have used the same Wi-Fi connection for both laptops or used the same payment information. The the chances of cheating a casino successfully is very slim because there are sophisticated ways casinos use to fish out multi accounts that we may not know.
Multiple account is something that user must avoid to prevent the case like that. A casino really don't like when they see their member have 2 or more accounts in their business so they will do something that will affect to the user.
We don't know how casino can identify their members who have more accounts but casino can do that with their teams. Detecting the pattern that every user may be one of many ways that casino can do but I am sure the casino can do a lot because that is their business.
They will make sure that no one will cheat them and run with the money. If casino find user cheat them, casino will not tolerate especially if they write that in their rule that say only 1 account per user.