Building Geometry Stops UTickableWorldSubsystem Ticking

Can be mitigated by reopening the Level.
There is a repro project provided by the licensee on the case ticket.

1) Create a class that extends UTickableWorldSubsystem
2) Override the Tick function
3) Add a Log message to the Tick function
4) Observe the message displayed each tick cycle in the Output Log window
5) Rebuild the level Geometry by pressing Build->Build Geometry
6) Observe the log messages ceasing to display in the Output Log window