I don't have 'Standing Ovation' but a couple of other varieties, and don't see rising crowns on any of them.

It could be from heaving, and it could be from inadequate drainage or seriously compacted clay soil under it.

You might try replanting it next spring, and make sure it has good drainage and tilth.

donn, I think you must be spot on -- we do have heavy clay here and I probably wasn't aggressive enough about prepping the soil. I'm seeing the same phenomenon (to a lesser degree) with another grass (Sea Oats 'Rivermist') in another border too, so I'm guessing that the grasses' roots penetrate deeper into the soil? Since the other plants in the same borders, planted around the same times, are not doing the same 'heaving'...