Recently, Michael had informed Onyx to inform him in case someone came looking for him. He did not want the same situation as when Bob and the other few people came looking for him.
Mostly, Onyx was previously paying attention to those that tried to look for Michael's information. As for where exactly they were, Michael did not pay much attention.
But ever since that incident where Bob came with Gregory, Michael told Onyx to pay attention to the surroundings of the villa.
So, the moment that James came looking for him, Onyx immediately informed Michael. And at the moment, James was still at the entrance of the community, having just entered.
Michael was quite curious about why this guy came looking for him. After all, ever since he left, they had never contacted each other again.
While it had only been 3 days since James first came to try and assassinate Michael, to that guy, it probably had been quite a long while.
