Thanks for your report. Do you mean "swap it with a port" on a map that already has invalid port placements (back from before this update)? Otherwise, I don't see how you would get an invalid placement by swapping two ports, and then an example would be appreciated.
- Build this arrangement:
- Port Village - Field - Port Village
- Go to the swap screen
- Select the Field
- Move the field to the right one (so that it swaps places with the rightmost port)
- Confirm
- You now have:
- Port Village - Port Village - Field
For comparison, if you did it differently...
- Build this arrangement:
- Port Village - Field - Port Village
- Go to the swap screen
- Select the second Port Village
- Move the port village to the left one (so that it swaps places with the field)
- Confirm
- You now have:
- Port Village - Field - Field