If you die during a single player game and choose 'respawn' instead of reloading, the construction drones no longer work.
After re-spawning then can be enabled once again by researching the technology, but will be disabled again after dying a second time.
This happens with only Construction Drones and Infinity mode enabled.
Here are two saves: One before and one after respawn: https://www.dropbox.com/sh/z16s52c573zj7jt/AAD-wz2_XDRHDHRw4kLLF8uya?dl=0 (Enemies to die by are just up north)
