My character is next to the payload but cannot move it, they haven't already moved the payload this round but they did move it last round. (I don't think this is relevant cus I've had the same character move the payload multiple rounds in a row before) They have sufficient movement remaining to move the payload.

Potential reasons/issues I can think of would be that it is on the other side of the payload to an enemy unit? (A demolisher so I'm not sure if my lancer is in threat cus I don't know it's weapons)

My nelson does also tend to be a bit janky with movement because of it's skirmisher feature and the many, many attacks I've layered onto it (disdainful blade, duelist III for the extra ram for a main melee attack, titanomachy mesh for the extra ram with my ram) so it could be that somehow interfering with it