It simply works! Charging upright does the trick, no matter how insane that sounds in reality it works!
I can confirm that there's no lose charging port, nor any other lose parts (like when shaking the device it's all firm & tight) and there where no issues at all with the device… it's unbelievable and unheard of, charging upright is at least a workaround!
I would love to hear a scientifical explanation for this specific problem because it's definitely not missing air circulation like mentioned before, it's also not a lose part from what I can tell!
It's so freaking insane… and thanks to that person posting this here first, it reduced the time I had to mess with this to 20 minutes, search the problem (fire 7 & 1%) brings this thread up!
I even signed up here just to say ‘thanks’ and confirm the “fix"!