c# - which is the fastest pattern scanning algorithm?

so I am coding a Sigmaker which searches for a certain Byte Array in Program Memory.

So far i'm making good progress, i'm just a little disappointed with the scan speed. with larger ranges it can sometimes take up to 5 minutes to get a valid result.

I'm using the following code right now:

IntPtr bytesRead;
ReadProcessMemory(process.Handle, baseAddress, moduleBytes, moduleBytes.Length, out bytesRead);

for (int modulePos = 0; modulePos < moduleBytes.Length; modulePos++)
{
   if (moduleBytes[modulePos] == patternBytes[pos] || mask[pos] == '?')
   {
       if (pos == maskLength)
       {
           foundstuff.Add(IntPtr.Add(baseAddress, modulePos - maskLength));
           pos = 0;     
       }
       pos++;
    }
    else
    {
        modulePos -= pos;
        pos = 0;
    }
}

I have accordingly searched for better algorithms and found the following: KMP Algorithm for Pattern Searching

Reading that, I added a KMP Algorithm to my project and after hours of work i have to realize that despite different codes and several rewrites the kmp algorithm is in the end 3-4 times slower than the code i used before, which doesn't sum up with the multiple comments in different threads that the KMP Algorithm would be the fastest one for my Work?

So did I do something wrong or is the Algorithm that I use actually the fastest Method for my Signature Scanner? Are there better Algorithms?

In case I did something wrong, I'll just add the Code here that I used:

IntPtr bytesRead;
ReadProcessMemory(process.Handle, baseAddress, moduleBytes, moduleBytes.Length, out bytesRead);

//converting ByteArray to HexString for the Algorithm
string data = ByteArrayToHexViaLookup32(moduleBytes); //will look like this "0F A2 03 00 01.."

//algorithm
int[] value = SearchString(data, pattern);
//Output = Offset of the found pattern

Here is the SearchString(data, pattern) Module