My liriope has changed from when it was younger, so I think that an older clump would change.

At the same time, there are several varieties that are just termed as liriope. That would lead to a difference in what you perceive for the leaves, also.

If you like your original grouping, you can split up clumps or plant some of the berry seeds.

If the plant is now growing under shadier conditions than where it was grown prior to your purchase, the newer leaves can become larger and paler to compensate for the lower light level. They also appear in the photo to have become softer in texture. That is a normal response for the changed conditions and/or just being younger leaves.

It's planted on the west side of my house so it gets quite a bit of shade, but is then hit by the hot Texas afternoons. I planted it in a small area leading up to my front door. I liked it because it was shorter than most of the liriope plants, so I'm disappointed the leaves are longer and bigger now.