Which suggests to me that if you’re only struggling to get communication with the headlamps then there is a problem with just that system, which is why they’ve dropped. So I’d be checking out wiring visually to start with. The lights work so there is no issue there, ͏You can hear the motors buzzing away so they must be working, it’s possible (but extremely unlikely) that both headlight tilt mechanisms have stripped simultaneously, but I really really doubt it.
You’ve fitted a new lsv for your lights on the back axle so that should be fine, so you need to focus on the wiring that connects the 2 together. If you can reestablish comms to the headlights I’d imagine you’d get your beam level back. You need to find the cable that goes from the lsv to the headlights and check that condition first, if it’s getting a false or no signal it will just go to one of two extremes depending on the value it’s getting, either facing the floor or blinding commercial flight pilots. I’d not worry about ground points but just check the wiring from the back to the front, it’s even possible that the exhaust had melted the cable.