dhiab

i think it's because when you eat below your BMR (300-400 less) your body tends to go on starvation mode thus not seeing any noticeable changes.

since your bmr is 1816 and you have been eating 1300-1400 per day your metabolism probably slowed down, i would suggest you gradually increase your calorie intake to 1800 in a 2-3 week window and see the results.