That does not sound good! Initially I’d say you have a bad power supply, but you said you replaced it. Please speak with the seller about a replacement.
Discussion
About 6 months old, its melted plastic on the base it gets that hot. I've replaced with a Supra seller sent a voucher code.
The only thing that visually looks off is some discolouring/ darkening around the positive where the barrel jack connects to the board.
It should not get that hot. The kinda sounds like a bad barrel connector