What has been your watering schedule for the new sod? How often and for how long did you water it?

Did you roll the sod down after it was installed? For small areas you could simply walk on every square inch of it.

Don't use any pesticides or herbicides on new lawn.

Is your soil mostly sand? If so you don't need to loosen it, because it doesn't compact the same way clayey soils do.

Did you add soil/sand to raise the area where it used to puddle? Why is it different now?

Can you post a picture of the suffering sod? The best lawn pictures are taken on a cloudy day or in the shade. Need a picture from 6 inches away and from 6 feet away.

I will try and get a picture, I had taken some but you really couldn't tell by looking at it. Thanks, you gave me a lot of food for thought to consider.