Instruct: Classify a given Amazon review into positive or negative sentiment.
Query: the top does not fit

I bought this after reading the reviews here. It arrived this afternoon but the top does not fit. There is a gap. I called Nesco and was told it might because of sitting and I should run it for an hour and see. I have run it for an hour but it still is the same. I don't know if I happen to get a bad one or this is normal so I am hoping to get some help. Nor sure if I should send it back before even trying it.