Why won't my Frozen Synapse units obey my commands?

I’m having lots of trouble getting units to behave in Frozen Synapse. Sometimes they just ignore my commands.

Here’s an example. I have a grenadier who currently has no orders. I’m asking him to move, but instead, he just stands there getting shot to death.

I’ve tried clearing focus and cancelling aim, but he still just stands there instead of following his waypoints. What gives?