It's probably because the calorie maintenance is a range and not a set number so you have to adjust accordingly so if you eat less -> you move less -> tdee goes down. All those while you feel lower energy and hungrier. That's where exercise comes in as a satiety regulator.

If 200-400 kcals deficit doesn't work, just lower by 100 more each week until you get to a desired weight loss rate.

I've found great success with this approach and also changing my thinking to 'is this thing something sustainable and healthy long term?'. Like of course I can lose a lot of weight fast with a huge deficit, but then I'll just default to my initial habits and gain it back.