It might not be software. The headlight has 3 wires going to it: +12V, ground, and LIN bus. The LIN bus wire controls everything that's going on in the headlight assembly (low beams, high beams, DRL, turn signal, adjusting beams vertically/horizontally). If the two power wires have power going to them but the LIN bus wire is disconnected, there is a failsafe that just keeps the headlight low beam on. It's possible that there's a software issue that keeps the headlight and vehicle computer from communicating, where it would go into that failsafe mode. It might not be possible to fix through an update, so the headlight computer or one of the vehicle computers might have to be replaced (BTW, Tesla would replace the whole headlight and not just it's computer). It's also possible that the LIN bus wire is shorted out damaged somewhere and they would have to find and replace the damaged harness. Best to let Tesla Service take care of it under warranty.
I'm curious: do your turn signal and high beam work normally on that side?