I'm the same height as well, riding a medium. That said, I think torso and lower body measurement factors into sizing. I went to a Specialized store and separately, to my LBS. Both took measurements and recommended the medium SL.
I am 5'6" and size small on my 2019 Levo and just ordered SL in size small too. Specialized said to stick with size small, should be very similar reach. All depends on your body and how you feel on the bike. I would feel that a medium would hinder handling for me, as too big.