Building Stacking machine learning model using three base classifiers
No, in generally speaking, even minor changes should affect your performance. Changing your meta-model should normally have a visible impact in your model's performance.

Two things you can try:


Check for any problems in your code.
Maybe your test set size is really small. For example if you have 5 test samples, it isn't difficult for all models to get 4/5 (i.e. 80% accuracy). As your test size increases so should the variance of your models' performance.