Surface Pro 4: New Battery, powers+charges only while plugged in

I installed a new battery in my Surface Pro 4 (didn’t see an option for that device). I plugged it in, powered on smooth, and charged up to 100% to begin calibrating. Once I unplugged it to continue calibrating, it goes immediately black and I have to plug it back in to reboot. I’m certain everything plugged in correctly, I followed the video closely. To my understanding, the battery “tab” just slips under the board and sits underneath the tabs to connect. Am I correct in thinking this, or have I made a dire mistake?

Taskbar icon has a plug and a full bar (didn’t start out full when I first started up), so it is recognized and taking a charge. Battery diagnostics recognize a battery is connected. Is it possible the battery could be defective? Or do I need to crack it open again and check on something I may have overlooked.