new type of tyles for Wyps?

I am playing Wyps ascending. There are now tiles which have a hexagonal shape (most tiles are round). It seems those tiles cannot be swapped. I didnt find anything in the rules about them. Can somebody tell me about them?

They are, in fact, octogonal not hexagonal :-)

It's been a year or so since this variant was introduced. You can read more about it here.

The key is that in Ascending WYPS the tiles can be flipped only once. Once they are flipped they can't flip anymore.

The octagon is the shape of a stop sign. The tile has stopped changing color.