I can't tell much from your post because there's little on what the old and new set was. As we get bigger settings the pixels are amplified so if you went from 32 inch to 65, you might see what you didn't before.
Anyhow, you have a new set and have warranty and support from maker and seller. Call them now before you have to keep it.
I just set up my new tv purchased yesterday a 65 inch Samsung UN65KU6290FXZA. The picture is pixelated in certain areas and lags when frames change. I confirmed with my satellite provider HD box channels and settings are enabled. I never had the problem with an older LCD Samsung I just replaced.
Thanks

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