What's the bike? An NVX fork is generally for hybrid use, light trail at the most.
The left hand leg has a coil spring, the right hand has the damping cartridge. The lockout is hydraulic, restricting the flow of the oil in the damper cartridge, that's why there's a little movement even with the fork locked. It's unusual for these to bottom out on the street. If that's the case I would suspect a broken spring. Have you slackened off the spring preload?
At the bottom of each leg is either a 10mm nut or a 5mm hex bolt. If you undo these the slider will pull off the stanchion. You'll probably find the insides will be full of water and emulsified grease. Clean the insides and the chrome stanchions. Light scoring on the chrome is acceptable, deep scratches or corrosion means it's a scrapper. Use wire wool to clean the chrome then regrease and reassemble and that should improve the action but if you're constantly bottoming out the fork then you need something stronger.
Look at the Epicon model if you're using the bike hard off road.