This is what happens if you are a perfectionist. I wanted to have a perfect fitting coro, measured grid to grid, thinking the connectors will create the right space to get in the coro. WRONG! You don't have straight angles at all.
You can correct it though without wasting your coro. Just carve your coro once more, next to the other carve. This time, measure connector to connector (on the inside limit) of the cage. You can carve it only on two sides to correct it, not four, it is faster. You can not see the mistake from far, just if you stay really close, as I did with the picture.