It's possible, my friend. When a miner successfully mines a block, they have the option to either broadcast it to the network or keep it private and start mining a new block on top of their own secret one. This is referred to as "selfish mining."
If this happens frequently enough, it can result in two different chains emerging with different transaction histories. This is known as a "fork," and it can create confusion in the network until consensus is reached on which chain should be considered valid.
So yes, someone could potentially be hovering in another chain if they are engaging in selfish mining behavior and keeping their mined blocks private for an extended period of time. However, this type of activity can also lead to negative consequences for the miner if discovered by other participants on the network.