Of course all boards are tested at factory for many small things, but this will never cover every single aspect. Read more about that on ROCK 3A defect notice so You will get idea how this works. Radxa is doing their best to catch as much as possible faulty boards on production and probably Your board was ok at that time.
Your sbc could be damaged in transport or even by ESD by Your touch, other possibilities are with Your charger, heat, moisture, handling, bad cable and possibly many other unfortunate things, we can only guess. Of course also it could have some IC defect that occured later and then probably more boards will share same problem (let’s hope it’s not that). Hopefully when You receive replaced board You will be able to run it.