New MacBook pro stops charging at 97%

That is only slightly unusual, probably because your Mac is new.

Normal operation is to recharge to about 92 percent under ordinary circumstances, and 80 percent when Optimize battery is ON AND your recent usage suggests you do not draw the battery down deeply.

Substantial software and hardware resources are monitoring battery and charging conditions multiple times a second. Your Mac will NEVER over-charge.

That computer is a battery-CAPABLE device. It is not optimized as a battery-operated device. (It is NOT an iPhone.)

Your computer performs best when connected to AC power. It can use the full output of the Power Adapter AND when doing especially challenging work will also freely "borrow" power from the battery. In some cases, even with the power adapter connected, the charged state may decline during stressful work.

When used only on battery, your computer has no extra cushion of power, and may perform more slowly. However, for ordinary non-stressful tasks this may not be objectionable (possibly not even noticeable.)

In general, you should ALWAYS connect AC power when it is possible to do so, and only run on batteries (which could be somewhat slower) when no AC sources are at hand. Your Mac will NEVER over-charge.

<< why Apple support doesn't have answers to this when I chat with them. >>

That is an artifact of the WAY those question are answered on Apple support versus Apple discussions.

Your call gets sent to the "next available" agent, regardless of whether they have expertise in the narrow area of your inquiry. When Apple Support agents have time for extra training, they get training on "How to be nice to customers."

Readers here are using their computers all day every day. Your query may be read by multiple readers who may say "I dunno" and pass you by. Typically, only readers who have something to add will respond. That responder may have developed deeper expertise in narrow technical areas than a random Apple Agent.

it is not normal to stop at 97 percent.

what you meant to ask was

¿is my Mac DEFECTIVE?

absolutely NOT! it is working great!

After a few cycles of charging "all the way up" it will likely revert to charging to about 92 percent before it stops, and that is what is expected once it "knows where FULL is".