The answer is no. “Starvation mode” isn’t affecting your ability to lose weight because it isn’t actually a real thing.
The popular opinion is that “starvation mode” occurs when you consume too few calories, which causes your metabolism to slow down so much that weight loss becomes impossible and can even result in weight gain. This whole notion is a myth. Calorie restriction will not stop weight loss altogether and it certainly won’t result in weight gain. As long as you create a calorie deficit (whereby you are burning more calories than you are consuming) you will lose weight – there are no ifs ands or buts about it.
That being said, your body will respond to long term calorie restriction by becoming more efficient and burning fewer calories to perform necessary daily functions. This metabolic adaptation can slow weight loss, but as long as a calorie deficit still exists it won’t prevent it.
So, if you feel like you’re doing everything right, but you still can’t lose weight the explanation is likely a simple one- you are either underestimating your calorie intake or you are overestimating your activity level and as a result you are not burning more calories than you’re consuming. Its also important to keep in mind that severely restricting calorie intake is linked to periods of over-eating so creating a smaller calorie deficit with the goal of losing weight more slowly is likely to be more sustainable and will allow you to be more successful in the long run.