Nether portal block invisible in front of another nether portal block

When you place 2 nether portals parallel to each other, the one closer to you has invisible (wireframe only) portal squares where they touch the other portal (see screen shot) This seems to be related to the update where you can't see water through ice that’s right next to it.

The screen shot shows a 3x3 interior portal in front of a classic portal. (If you look from the opposite side, the classic portal appears empty)

However, if you have 4 portals in a row, then you can see the third one away from you just fine!