I'm not quite sure if these are bugs or intentional, as they've been in the game for quite a while, but may as well comment.
Firstly, Lycus' shield doesn't charge when he's jumping or sprint jumping. It charges when he's walking, jogging, sprinting or sliding, but not when he's jumping, even if the jump is moving him forwards.
Secondly, his shield doesn't charge when he's carrying the encoder, or when he's carrying Schneider, on the In Medias Res mission. It does charge when he's carrying other objects though, like the bombs on Short Fused, or Kuzmann's head on Upside Down.