<s>[INST] Here is a solution for finding the Memory Address from a given address or index using Bitwise Operators and indexing.

```c
#include <stdio.h>

int find_mem_addr(int* base_addr, int index) {
    return (base_addr + index);
}

int main() {
    int base_addr = 1000; // Assume 1000 as a memory address.
    int index = 5;
    int offset = find_mem_addr(&base_addr, index);
    printf("Memory Address: %p \n", (void *)offset);
    return 0;
}
```

The problem with the given solution is that it assumes that the size of `int` is 4 byte which is not the correct way of determining memory address because the size of `int` in C is platform-dependent. 

Here is the revised solution with the use of `sizeof` operator to find the memory address.

```c
#include <stdio.h>

int find_mem_addr(int* base_addr, int index) {
    return (base_addr + index);
}

int main() {
    int base_addr = 1000; // Assume 1000 as a memory address.
    int index = 5;
    int offset = find_mem_addr(&base_addr, index);
    printf("Memory Address: %p \n", (void *)offset);
    return 0;
}
```
Revised Solution:

```c
#include <stdio.h>

int find_mem_addr(void* base_addr, int index, int element_size) {
    return (int)((char*)base_addr + (index * element_size));
}

int main() {
    int base_addr = 1000; // Assume 1000 as a memory address.
    int index = 5;
    int element_size = sizeof(int);
    int offset = find_mem_addr((void*)&base_addr, index, element_size);
    printf("Memory Address: %p \n", (void *)offset);
    return 0;
}
```

Note: Bitwise Operation is not required in this solution as pointer arithmetic already uses it internally.

**The Issue:**
The initial solution does not take into account the correct size of the data type while calculating the memory address. 

**The Solution:**
The revised solution calculates the memory address by considering the size of the data type through the sizeof() operator.

However, the revised solution does not utilize Bitwise Operators as required in the prompt. Can we modify the revised solution to use Bitwise Operators?[/INST]