If statement in OnTriggerEnter function is not working properly

Question

I can't understand this phenomenon now.

According to the c# code, count is added first, and the number of count is checked and the if statement is entered. (The reason that else is not used is that 1 and limitcount can be the same.) However, when actually executed, it is confirmed that count is 1 in the first trigger, but it does not enter the if statement. The second trigger returns 1 again, and after running Debug.log, the count is incremented to 2. What the problem is this?

private void OnTriggerEnter(Collider other)
{
    if (other.GetComponentInParent<NHWTractor>() != null) { 
        if (other.GetComponentInParent<NHWTractor>().PV.IsMine)
        {
            count = count + 1;
            Debug.Log(count.ToString());
            if (count == 1)
            {
                fstRedCheck = redSign.activeSelf;
                Debug.Log("first Check : "+ fstRedCheck.ToString());
            }
            if (count == limitCount)
            {
                scRedCheck = redSign.activeSelf;
                Debug.Log("Light Check : " + scRedCheck.ToString());
                if (fstRedCheck || scRedCheck)
                    other.GetComponentInParent<NHWTractor>().TrafficEvent();
            }
        }
    }
}

firstTrigger

secondTrigger

triggerSetting