Turns off after disconnecting the usb-c cable - not charging?

After I replaced the shell of my controller, I noticed the controller wouldn't turn on after disconnecting it from the usb-c cable. Hence:
- I bought a new battery
- replaced the battery with the new one
- charged it a bit
- unplugged the usb-c
- turned it on.
- noticed the xbox light turn on for 2 seconds, then off. Thought it was fine. Just didn't power it enough.
- notice later the issue I had previously was still there

namely:

- plug in the controller, and it works fine.
- unplug and it becomes unresponsive, not even a light.