shield_max, energy_max, and weapon_cooldown are always zero (for replays)

I am looking a replay as observer (player_id = 0). During onStep() is called, I read the following values of all units:

- health
- health_max
- shield
- shield_max
- energy
- energy_max
- weapon_cooldown

For the replayes I watched the values shield_max, energy_max, and weapon_cooldown are always zero. Although shield and energy are not always zero. Is this a bug related to replays or observers? Can you fix it?