Is the Rock 64 something strange?

[kometchtech]

In this case, should we suspect hardware (Rock 64)?

No.

... always suspect a bad, cheap, defective or fraudulent SD card;  its that simple.

We recommend Samsung 32G Class 10 Evo Plus cards !   Also, you can test your cards for fraud;  there are many fraudulent cards out there;  please read this link.

Thanks for the reply.

Is Samsung EVO plus? If EVO is useless, I feel pretty severe with regard to the corresponding microsd.
Let's buy Evo plus for the time being and try it.

Best regards.