Oil pressure light

sender switch may be plugged, that would be nice and easy, that isn't the way things go usually, then the filter could be defected or wrong part number , probably not, could be why it was up for sale when you recently purchased it. holding above that 1200 rpm will be starving the bearings and will throw a rod or seize the pistons in a few minutes if the flow has slowed to this point. only thing I can deduce is the flow is restricted at the oil pump pickup in the pan from burnt sludge on the pickup tube screen, I once was able to send a probe thru the drain hole and relieve one by poking thru the screen! a worn out oil pump would probably act the opposed way by lousing pressure at low r.p.m. so I say pull the pan and repair the pickup screen

Had the same issue,replaced dashboard after mechanic checked oil pressure and replaced sender unit.