It’s unclear whether the hub was in your present home when you purchased the hub (and home?), or whether this is a hub you purchased from someone and brought into your home.
You say that you see the previous owner’s devices, but are those devices still connected to the hub in its present home?
If this is a j hub that you purchased from someone and then brought into your home without the prior owner’s devices (but with the devices still in the hub’s database and radio databases), then the hub is probably choking, trying to communicate with its now-estranged devices. In this case (and only this case, where a hub is transferred to a different owner), you need to do a Full Reset of the hub and register the hub.
Again, Full Reset is RARELY needed - only when the hub is being transferred to a new owner, because it de-registers the hub, resets the internal database, and resets the radios. It’s an out-of-the-box experience.
If this is really your situation, go to:
your.hub.ip:8081
and do a Full Reset.
You will need the hub’s MAC address (from the bottom sticker) as the login password. If, as you say, you currently have access to the hub, then the easiest way to get the MAC address (rather than typing it in) is to go to Settings, Hub Details, and copy the MAC address, then go to the port 8081 URL above and paste the MAC at the login.
Did you put your hub into inclusion mode, and then put your lock into inclusion mode?