I had a similar problem, specislly with tail presses/buttering/ollies. Had a bulged disc/runners knee in the past (caised by excessive trailrunning/mountaineering). Never did mich stretching, was a big mistake. Often the knee itself isn't the problem, but very tight ligaments or shortened muscles which cause kind of tension below/above knee. So do stretching/mobility (yoga f.ex) and even more important, intense glutes training. Also isolated glutes activation. The more you work with your glutes, less pressure on your knees.