Nose rises after touch down

When landing, forward pressure should be applied until you’ve decelerated below 60 knots or so. This is due to ground effect. The plane is meant to fly and does everything possible to continue to do so and so you have residual air under the wings that will try to push up and keep the plane flying. You mentioned P3D so I assume you’ve been flying/simming awhile. You should know this, pilot or not. Even watching a few cockpit landing videos could easily give you this answer as well.