I love haunted places, but can't stay in them for long period of time.
The way you describe it, something is going on. Can't tell what.
If you allow, i would visit it sometimes, in my thoughts. Maybe something shows up.
But it is sure thing, if i would sell a house and something strange would be happening, i would never tell about it
It is not that it is connected to previous owner, maybe it can be location, or environment or just fate, something else. I can't never tell what it is until it shows up. So..