Why is my Normalized power always so different from my Average power.

I've noticed mostly everyone has very similar normalized power and averages while racing on Zwift, while mine is almost always 30-50 watts higher on normalized power.

Here are some of my last rides all distances around 20km +
173 avg 214 NP
184 Avg 220 NP
107 Avg 150 NP
162 Avg 198 NP

How much is this hurting my riding / ability and is it something to worry about?