Turboboost of 2018 MacBook Pro 13inch doesn't reach 4.5GHz with Cinebench test

Hello, I have the 2018 MacBook Pro 13 inch with Core i7, base speed 2.7 GHz and turbo boost to 4.5 GHz.

I performed a few test with it (Cinebench and the Intel Power Gadget), and the speed only spikes for a few milliseconds to 4.10 GHz, and then goes down to 3.1 GHz. The temperature is stable at around 99 Celsius then. I have never seen it reach 4.5 GHz.

Is this normal? Am I misinterpreting the results of the cinebench and intel power gadget test? or is the a problem? I bought the laptop like a month ago.

Cheers!