Dynamic memory allocation issue when copying to new array

I am creating a function to split a char * into an array of other char * based on a target (which can be " ", "a", etc). In this example, I am using a white space (" ") to split my char * into an array of char *.

However, I am having some difficulties dealing with the dynamically allocated memory. I allocated memory for both the array of char * that I will be returning as the split function return value, and another one to copy each separated const * that I am reading from the main char * parameter.

#define MAX_SIZE 65535
#define MAX_SPLIT_SIZE 1023

char** a_split(char * x, const char * target, int sn){

    char ** sa = nullptr;

    size_t t_len = strnlen(target, MAX_SIZE);
    if(t_len < 1 || t_len > MAX_SIZE){ return sa; }

    int split_num = 0;

    if(sn > 1 && sn < MAX_SPLIT_SIZE){

        sa = new char * [sn + 1]();
        split_num = sn;


    }else if(sn == -1){

        sa = new char * [MAX_SPLIT_SIZE + 1];
        split_num = MAX_SPLIT_SIZE;
    }else {
        return sa;
    }

    char * ptr = x;
    char * mi;                                              // Match index.

    int i = 0;                                              // Index of 'sa' array.

    while((mi = std::strstr(ptr, target)) && split_num--){

        size_t dif = mi - ptr;

        char * n_cstring = new char[dif + 1]();

        memcpy(n_cstring, ptr, dif);                        // Copying content to new string.

        sa[i++] = n_cstring;                                // Append new string to 'sa' array of split strings.

        ptr += dif;

        ptr += t_len;

        delete [] n_cstring; // <------- This is causing some weird errors.
    }

    if(mi == nullptr){

        sa[i] = ptr;
    }

    return sa;
}

int main(int argc, char * argv[]){

    char  c[] = "I love Thanos";

    char ** x = a_split(c, " ", -1);

    for(int i = 0; x[i]; i++){
        puts(x[i]);
    }

    return 0;
}

I found out that when using 'delete [] n_cstring', instead of outputting the char *'s separately (like in "I" "love" "Thanos"), it is outputting "love" "love" "Thanos". It is making this kind of repetition for every example. Why is 'delete' doing this?

Also, as I am returning a dynamically allocated array ('sa'), where would you recommend me to delete it? - the main function does not recognize 'sa'.