Can switch/case be used inside if/else? [closed]

I have to run two conditions one at a time, so I am using if/else but in one condition I have to use switch/case to run different screens and loop should run in while.

The code is below:

void app_main()
{
 uint8_t scrn = 0, cntr = 0;
 while(1)
  {
    if (ble_con_sta)
    {
      display_app_acess();
    }
    else
    {
      switch(scrn)
      {
      case 0:
        scrn_time();
        break;

      case 1:
        scrn_temp_humid();
        break;

      case 2:
        scrn_dose();
        break;      
      }

      cntr++;
      if(cntr>200)
      {
        cntr=0;
        scrn++;
        if(scrn>2)
          {scrn=0;}
        Clear_Screen(0);
      }
    }
  }
}

But is not working as required, the code is stuck in scrn_time();

But if i am doing likw below then its working

  {
      switch(scrn)
      {
        case 0:
          get_FP_ID();
          if (ble_con_sta)
            {display_app_acess();}
          else
            {scrn_time();}
          break;
        case 1:
          if (ble_con_sta)
            {display_app_acess();}
          else
            {scrn_temp_humid();}
          break;
        case 2:
          if (ble_con_sta)
            {display_app_acess();}
          else
            {scrn_dose();}
          break;      
      }

      cntr++;
      if(cntr>200)
      {
        cntr=0;
        scrn++;
        if(scrn>2)
          {scrn=0;}
        Clear_Screen(0);
      } 
  }

I have tested the code in both ways and also by running only switch case, all the functions are working fine.