Why does the CPU load increase in an Angular application?

Question

Angular

There is an application in which a bunch of so-called slides, in each slide a list is displayed, in each element there are three fields in which components similar to the select are implemented, with added functionality. At first, everything is fine, but as soon as you start choosing values ​​(multiselect) in the select, the load on the CPU starts to grow, then it drops a little, but not to the same level as it was before. And the more changes you make, the more the load grows. As a result, everything comes to the point that the whole app starts to slow down wildly and the CPU load is 100%.
PS: Slides can be added, removed, merged, the number of items also changes, in general the form is quite interactive and it seems that with any change in the model, the load on the CPU starts to grow. Angular 4