Why my input gone after input into a structure through a function?

So below is my program that contain several function about information of employees that were stored within a structure such as display all of them, search by entering ID or date joined and also edit or add new record. So my problem now is after i use the addRecord function within my program, then it navigated back to the menu, when i choose to displayAll, the new employee's information that i have just entered through the addRecord function is all gone, can someone please help me to spot where my mistakes are? Appreciate it a lot.

#include <stdio.h>
#include <string.h>
#define MAX_SIZE 20

struct Date {
    int day;
    int month;
    int year;
};

struct Employee {
    char employeeId[4];
    char name[20];
    struct Date date;
    char department[15];
};

void displayAll(struct Employee em[MAX_SIZE], int employee);

void search(struct Employee em[MAX_SIZE], int employee);

void viewRecord(struct Employee em[MAX_SIZE], int employee);

void editRecord(struct Employee em[MAX_SIZE], int employee);

addRecord(struct Employee em[MAX_SIZE], int employee);

int main()
{
    int nEmployees = 5;
    int menuChoice;

    struct Employee emp[MAX_SIZE] = { { "E01", "Alice Chan", {5, 12, 2008}, "R&D"},
                                      { "E02", "John", {9, 12, 2011}, "IT"},
                                      { "E03", "Vivian", {3, 3, 2015}, "HR"},
                                      { "E04", "Alice Chin", {4, 4, 2011}, "IT"},
                                      { "E05", "Vivien Tan", {5, 3, 2015}, "HR"}
    };
    
    do {
        printf("\n\n\nHello human, what do you want to do? \n");
        printf("1 for display all employee's information. \n");
        printf("2 for search based on date joined. \n");
        printf("3 for search based on ID. \n");
        printf("4 for editing employees' info. \n");
        printf("5 for adding new employee's info. \n");
        printf("0 for exit. \n");
        printf("> ");
        scanf("%d", &menuChoice);
        
        if (menuChoice == 1) {
            displayAll(emp, nEmployees);
        }
        
        else if (menuChoice == 2) {
            search(emp, nEmployees);
        }
        
        else if (menuChoice == 3) {
            viewRecord(emp, nEmployees);
        }
        
        else if (menuChoice == 4) {
            editRecord(emp, nEmployees);
        }
        
        else if (menuChoice == 5) {
            addRecord(emp, nEmployees);
        }
        
        else {
            printf("The choice is invalid :(. Please try again. ");
        }
        
    } while(menuChoice != 0);
    
}

void displayAll(struct Employee em[MAX_SIZE], int employee) {
    int counter = 0;
    
    printf("Employee Details : \n");
    printf("-------------------\n");
    printf("Employee ID    Name           Date Joined    Department\n");
    do {
        printf("%-15s%-15s%-2d%-3d%-10d%-s\n", em[counter].employeeId, em[counter].name, em[counter].date.day, em[counter].date.month, em[counter].date.year, em[counter].department);
        counter++;
    } while(counter < employee);
}
    
void search(struct Employee em[MAX_SIZE], int employee) {
    int counter = 0;
    int search1, search2;
    printf("Enter the month and year to search (exp : 12 2008): ");
    scanf("%d %d", &search1, &search2);
    printf("Employee Details : \n");
    printf("-------------------\n");
    printf("Employee ID    Name           Date Joined    Department\n");
    do {
    if(search1 == em[counter].date.month && search2 == em[counter].date.year) {
        printf("%-15s%-15s%-2d%-3d%-10d%-s\n", em[counter].employeeId, em[counter].name, em[counter].date.day, em[counter].date.month, em[counter].date.year, em[counter].department);
    } 
    counter++;
    } while(counter < employee);
}

void viewRecord(struct Employee em[MAX_SIZE], int employee) {
    int counter = 0;
    char search3[10];
    
    printf("Enter the ID to search : ");
    scanf(" %s", &search3);
    do {
    if(strcmp(search3, em[counter].employeeId) == 0) {
        printf("Employee ID > %s\n", em[counter].employeeId);
        printf("Name        > %s\n", em[counter].name);
        printf("Date Joined > %d-%d-%d\n", em[counter].date.day, em[counter].date.month, em[counter].date.year);
        printf("Department  > %s\n", em[counter].department);
    }
    counter++;
    } while(counter < employee);
}

void editRecord(struct Employee em[MAX_SIZE], int employee) {
    int counter = 0;
    int editChoice;
    char choice[10];
    
    printf("Enter the ID you want to edit > ");
    scanf("%s", &choice);
    do {
    if (strcmp(choice, em[counter].employeeId) == 0) {
    printf("What do you want to edit ? ( 1 for name, 2 for date joined, 3 for department) > ");
    scanf("%d", &editChoice);
    
    if (editChoice == 1) {
        printf("Enter new name > ");
        scanf(" %[^\n]", &em[counter].name);
        }
    
    else if (editChoice == 2) {
        printf("Enter new date joined > ");
        scanf(" %d %d %d", &em[counter].date.day, &em[counter].date.month, &em[counter].date.year);
    }    
    
    else if (editChoice == 3) {
        printf("Enter the department > ");
        scanf(" %[^\n]", &em[counter].department);
    }
    printf("Employee ID > %s\n", em[counter].employeeId);
    printf("Name        > %s\n", em[counter].name);
    printf("Date Joined > %d-%d-%d\n", em[counter].date.day, em[counter].date.month, em[counter].date.year);
    printf("Department  > %s\n", em[counter].department);
    }
    
    counter++;
    } while(counter < employee);
}

addRecord(struct Employee em[MAX_SIZE], int employee) {
    printf("Enter the ID > ");
    scanf(" %[^\n]", &em[employee].employeeId);
    
    printf("Enter the name > ");
    scanf(" %[^\n]", &em[employee].name);
    
    printf("Enter the date joined (exp: 28 8 2002) > ");
    scanf(" %d %d %d", &em[employee].date.day, &em[employee].date.month, &em[employee].date.year);
    
    printf("Enter the department > ");
    scanf(" %s", &em[employee].department);
    
    employee++;
    
    return employee;
}