Hi guys,
Everytime i cut out shape on models that are round or rounded i get some strange hard shapes and the model is not smooth anymore!
It really talking a lot of time and I don't understand how.
I can use booleans or i can do it manually but it keeps giving me these strange hard parts.

Now what i show in this picture if of course with n-gons but it doesn't matter if I fix that or not those hard lines that seem to be there for no reason keep staying there.

How does that happen? Again this happends with and WITHOUT cutting out with booleans.