[Bug] The semaphore is not removed upon demolition

Hi!
There is a bug where, if a semaphore on a structure is active and the structure is subsequently demolished, the semaphore remains in place and is not removed.

Update:
If I build another structure somewhere else and activate the semaphore, the problem goes away, and the semaphore that was left behind in the empty space disappears.
So, I'm not sure if this should be considered a bug...