Turn it off and use a thin needle to remove the silicone and then check the charging again.
The phone opens with a guitar pick without any heating as far as I remember.
Ask plamen for those technical details.
here is the exploding diagram, BraX3 - Full Device Specifications - #20 by xancudo
it seems that case opens from the side of the screen, not the back side, you can also watch the assembly GIF-like video if you scroll down on the Indiegogo website, the port is soldered on a small daughter board, https://www.indiegogo.com/en/projects/braxtechnologies/brax3-the-most-privacy-friendly-smartphone#/section/project-story