The port doesn't need to be destroyed during its built. Now the port is destroyed, when any military building reach its position. Steps to reproduce the bug:
1. Start building a port from an expedition
2. Conquer the territory with own military building
Next step should be:
3. The port is continuing its built and end the built
But it is:
3. The port is destroyed
The port doesn't need to be destroyed during its built. Now the port is destroyed, when any military building reach its position. Steps to reproduce the bug:
1. Start building a port from an expedition
2. Conquer the territory with own military building
Next step should be:
3. The port is continuing its built and end the built
But it is:
3. The port is destroyed