Buffer Overflow Exploit Issue

I am trying to complete a a buffer overflow that involves overwriting a function pointer. The vulnerable C program is as follows:

#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>

void win()
{
  printf("code flow successfully changed\n");
}

int main(int argc, char **argv)
{
  volatile int (*fp)();
  char buffer[64];

  fp = 0;

  gets(buffer);

  if(fp) {
      printf("calling function pointer, jumping to 0x%08x\n", fp);
      fp();
  }
}

I've already run gdb on the program and found that the size of "buffer" is 72 bytes and the function address is 0x555546ca. So, I pipe in

python3.6 -c "print('A' * 72 + '\xca\x46\x55\x55')" | ./stack3

and get a weird result:

calling function pointer 0x55468ac3
Segmentation fault (core dumped)

After examining memory, I found that the buffer was filled properly with 0x41s, but the next two words (fp*) were 0x55468ac3 and 0x00000055. I cannot understand why the data is obscured in this way.