Hi @dominikmlkvy,
This looks like a hardware problem. Are there any visible signs of damage on the board, or perhaps an interrupted connection somewhere? It might help if you can provide photos of the device in it's current state with a sufficient resolution to examine the hardware.
If you are positive that you have not used the device in a way that is outside the intended operating parameters you can send the device for a replacement, but you may be charged some or all of the cost if the fault is due to improper use. Please contact [email protected] for further help.
We keep test logs of our devices before sending them out - it would help if you could provide me with a serial number of your device so I can check it, but I don't expect that it failed testing as we perform a final check before sending each product.
I hope this helps