I can't figure out why these two versions behave differently

Using Arduino Programming Questions
1

I've banged my head against the wall for a while now and figure I need some help. I have two sets of code that should be identical in terms of behavior, but they are not. In the first case I "brute force" the code:

void SetupAndIntrClass::watchdogSetup() {
        cli();
        /* Clear the reset flag. */
        MCUSR &= ~(1<<WDRF);
        
        /* In order to change WDE or the prescaler, we need to
         * set WDCE (This will allow updates for 4 clock cycles).
         */
        WDTCSR |= (1<<WDCE) | (1<<WDE);
        
        /* set new watchdog timeout prescaler value */
        // WDTCSR = 1<<WDP3 | 1<<WDP0; /* 8.0 seconds */
        //WDTCSR = 1<<WDP2 | 1<<WDP1 | 1<<WDP0; /* 2.0 seconds */
        //WDTCSR = 1<<WDP2 | 1<<WDP1; /* 1.0 seconds */
        //WDTCSR = 1<<WDP2 | 1<<WDP0; /* 0.5 seconds */
        //WDTCSR = 1<<WDP2; /* 0.25 seconds */
    WDTCSR =  1<<WDP1 | 1<<WDP0; /* 0.125 seconds */
    //WDTCSR =  1<<WDP1; /* 64 ms */  // seems to have issues on prototype
    //WDTCSR =  1<<WDP0; /* 32 ms */  // seems to have issues in lab
        /* Enable the WD interrupt (note no reset). */
        WDTCSR |= (1<<WDIE);
        sei();
    }

and in the other case, I try to streamline things with a if/else structure (or the commented out switch/case structure which also has a problem) as follows:

// prescale choices are (in ms) 32, 64, 125,250,500,1000,2000,8000
void SetupAndIntrClass::watchdogSetup(int prescale) {
    
    cli();
    /* Clear the reset flag. */
    MCUSR &= ~(1<<WDRF);
    
    /* In order to change WDE or the prescaler, we need to
     * set WDCE (This will allow updates for 4 clock cycles).
     */
    WDTCSR |= (1<<WDCE) | (1<<WDE);
        /* set new watchdog timeout prescaler value */
//    switch (prescale) {
//        case 32:
//            WDTCSR =  1<<WDP0; /* 32 ms */
//            break;
//        case 64:
//            WDTCSR =  1<<WDP1; /* 64 ms */
//            break;
//        case 125:
//            /* 0.125 seconds */
//            WDTCSR =  1<<WDP1 | 1<<WDP0; 
//            break;
//        case 250:
//            WDTCSR = 1<<WDP2; /* 0.25 seconds */
//            break;
//        case 500:
//            WDTCSR = 1<<WDP2 | 1<<WDP0; /* 0.5 seconds */
//            break;
//        case 1000:
//            WDTCSR = 1<<WDP2 | 1<<WDP1; /* 1.0 seconds */
//            break;
//        case 2000:
//            WDTCSR = 1<<WDP2 | 1<<WDP1 | 1<<WDP0; /* 2.0 seconds */
//            break;
//        case 8000:
//            WDTCSR = 1<<WDP3 | 1<<WDP0; /* 8.0 seconds */
//            break;
//    }

    if (prescale==32)
    {
        WDTCSR =  1<<WDP0; /* 32 ms */
    }
    else if (prescale==64)
    {
        WDTCSR =  1<<WDP1; /* 64 ms */
    }
    else if (prescale==125)
    {
        WDTCSR =  1<<WDP1 | 1<<WDP0;/* 0.125 seconds */
    }
    else if (prescale==250)
    {
        WDTCSR = 1<<WDP2; /* 0.25 seconds */
    }
    else if (prescale==500)
    {
        WDTCSR = 1<<WDP2 | 1<<WDP0; /* 0.5 seconds */
    }
    else if (prescale==1000)
    {
        WDTCSR = 1<<WDP2 | 1<<WDP1; /* 1.0 seconds */
    }
    else if (prescale==2000)
    {
        WDTCSR = 1<<WDP2 | 1<<WDP1 | 1<<WDP0; /* 2.0 seconds */
    }
    else
    {
        WDTCSR = 1<<WDP3 | 1<<WDP0; /* 8.0 seconds */
    }
    /* Enable the WD interrupt (note no reset). */
    WDTCSR |= (1<<WDIE);
    sei();
}

to call the first version of the function, I use

watchdogSetup();

for the second I use

watchdogSetup(125);

What am I missing???

I am using a ATMEGA328p in a standalone application. I should note that I declare the functions in the *.h files differently. For the first case I have

void watchdogSetup();

and for the second case I have

void watchdogSetup(int prescale);

Thanks in advance

2

/* In order to change WDE or the prescaler, we need to

  • set WDCE (This will allow updates for 4 clock cycles).
    */
  uint8_t v;

    if (prescale==32)
    {
        v =  1<<WDP0; /* 32 ms */
    }
    else if (prescale==64)
    {
        v =  1<<WDP1; /* 64 ms */
    }
    else if (prescale==125)
    {
        v =  1<<WDP1 | 1<<WDP0;/* 0.125 seconds */
    }
    else if (prescale==250)
    {
        v = 1<<WDP2; /* 0.25 seconds */
    }
    else if (prescale==500)
    {
        v = 1<<WDP2 | 1<<WDP0; /* 0.5 seconds */
    }
    else if (prescale==1000)
    {
        v = 1<<WDP2 | 1<<WDP1; /* 1.0 seconds */
    }
    else if (prescale==2000)
    {
        v = 1<<WDP2 | 1<<WDP1 | 1<<WDP0; /* 2.0 seconds */
    }
    else
    {
        v = 1<<WDP3 | 1<<WDP0; /* 8.0 seconds */
    }

    cli();
    /* Clear the reset flag. */
    MCUSR &= ~(1<<WDRF);
    
    /* In order to change WDE or the prescaler, we need to
     * set WDCE (This will allow updates for 4 clock cycles).
     */
    WDTCSR |= (1<<WDCE) | (1<<WDE);
    WDTCSR = v;
    /* Enable the WD interrupt (note no reset). */
    WDTCSR |= (1<<WDIE);
    sei();
}
3

Thank you!!!