On my 2006 Pathfinder the headlamps have melted in the housings. They still operate but plastic has dripped across the passenger side light and the drivers side is showing signs of it also beginning to melt. I beleive the lamps are original. It's a recovered stolen so no warranty.
That has been know to happen when someone puts in extra bright lights. You also may want to have the voltage checked in your car with the engine running. It could not be much over 13.5V
There is not much you can do to correct the damage other than to replace the lamp housings $$$$ You may want to replace the lamps if they are not standard.
There are aftermarket headlights that are half the weight of oem assemblies. If these were replaced because of an accident, that might explain it. I had some old stock new headlights I tried selling on ebay for 99 cents and they didn’t sell. My shipping was too high compared to the import ones and I get discount UPS rates. I can’t imagine those import ones lasting more than a year.
Since you didn’t buy it new, you don’t really know if the bulbs are stock. Sounds like they’re not. Get 'em out of there unless you like the Salvador Dali look.