Leetcode 10 - timeout issues - how to analysis the issue?

Leetcode10_timeoutIssue.cs

using System;

class Solution
{
    public static bool IsMatch(string text, string pattern) //"abc"  "a.c"
    {
      // base case 
      if(text == null || pattern == null)
      {
        return false; 
      }
      
      if(pattern.Length == 0)
      {
        return text.Length == 0; // true, "a", ""
      }
      
      return isMatchHelper(text, pattern, 0, 0); 
    }
  
    // "abbb", 1, "bbb" , "ab*", 0, "bbb" with "ab*"
    private static bool isMatchHelper(string text, string pattern, int textIndex, int patternIndex) // abbb, ab*
    {
        var lengthText = text.Length;
        var lengthPattern = pattern.Length;

        // base case
        if (patternIndex == lengthPattern)
        {
            return lengthText == textIndex;
        }

        var template = pattern[patternIndex]; //'a'      
        var isContainingStar = template != '*' && patternIndex < lengthPattern - 1 && pattern[patternIndex + 1] == '*'; // standalone "*"

        // base case - text string is empty but pattern string not emtpy
        if ((lengthText == 0 || lengthText == textIndex) && isContainingStar)
        {
            return isMatchHelper(text, pattern, textIndex, patternIndex + 2);
        }

        if (lengthText == textIndex)
        {
            return false;
        }

        // pattenrIndex < lengthPattern
        // single char match
        var visit = text[textIndex]; // out-of-index range // 'a'

        if (!isContainingStar)
        {
            var comparisonEqual = visit == template || template == '.';
            if (!comparisonEqual)
            {
                return false;
            }

            return isMatchHelper(text, pattern, textIndex + 1, patternIndex + 1);
        }

        // assuming that containing * 
        // return at least 2 branch, pattern a*, or .* 
        // match 0 time, match 1 time or more than 1 time 
        if (isMatchHelper(text, pattern, textIndex, patternIndex + 2))  // abbb, ab* 
        {
            return true;
        }
        else if (visit == template || template == '.') // match one time
        {
            var matchOneTime = isMatchHelper(text, pattern, textIndex + 1, patternIndex + 2);
            if (matchOneTime)
            {
                return true;
            }

            return isMatchHelper(text, pattern, textIndex + 1, patternIndex); // text = bbb, pattern b*b; text = bb
        }             // bbb  b -> false 
        // b == b || b == '.'  one time , bb match b -> false 
        // bb match b*b -> it will 
        return false;
    }

    static void Main(string[] args)
    {
        Console.WriteLine(IsMatch("bbbba",".*a*a")); 
    }
}