On low beam the left headlamp points higher than the right. On high beam they are pointed at equal height. I checked if the headlamp assemblies are installed properly with all the tabs in place - that is OK. Is this normal?

Pull the bulb and see if it is bent. If so, try to straighten it to 90 degrees off the socket. If you touch the bulb, be sure to clean it with alcohol or some other good de-greaser. Also be sure that it is properly seated in the headlight assembly.