Can build multiple porta-pods

Reproduction is easy:

1. Pause game.
2. Select pod and place it.
3. Click copy and place more anywhere.
4. Build all (not activate them until all built)
5.  Acticate all at once (scheduling is enough, dupe will go one by one).

When one of them is built you cannot copy or select from build menu, but as described above you can queue many of them and they will be built.