`netopt_state_t` is an enumeration type which is not necessarily 1 byte. If `uint8_t` is used, the cast `*((const netopt_state_t*) val` in `sx127x_netdev::_set`tries to read the real size, which can be more than the given length of 1 byte. Therefore, `netstat_opt_t` has to be used instead of `uint8_t`