Heavy Orbital Bombardment Stops Working After ACU is Transported

If you build the heavy orbital bombardment upgrade on the ACU, and then transport the ACU somewhere it stops working and will not fire missiles.
Deleting the upgrade and rebuilding it makes it functional again.
This does not affect the light orbital bombardment. It continues to function after transporting.

Reproduce the issue by building heavy orbital bombardment on the ACU, transporting it, and checking whether missiles fire; compare the result with light orbital bombardment. Trace the heavy and light bombardment behavior around transport, then verify that heavy bombardment still fires after transport without rebuilding the upgrade.

Written by the indexing model from the issue text.