Had the same issue today with my new MBP 16in. I customized it on the website and made some decent upgrades. The local store had stock, which was great. No need for shipping. Picked it up today and tried to power on. Battery indicator on screen showed red sliver. Plugged in charger for a bit with no change. This is really odd, because all Apple products come precharged. Mine was dead. After some phone calls to support, I ended with a local store rep. He said that most of these models sat in storage during covid and depleted that initial charge. Mine was a rare customization, and that meant it sat longer. Had I just bought and shipped online, then I wouldn’t have had the issue. He said that once the battery is depleted, new in box, and sits in that depleted state for a length of time; that it requires a battery replacement. Somehow you can’t charge it once it gets to this situation. Definitely a design flaw. How often to folks let their laptops die completely? Apple hasn’t officially released a product recall of unsold laptops during the covid time. He said that they had only just found out what is causing this issue. He’s had multiple. I have a scheduled appointment to swap with another new unit tomorrow. I’ll be trying it before leaving. Battery replacement is the only way to recover, if not able to return under return window.