Why might class nesting not work in sass?

Question

HTML

There is a lot of working code in sass. I decided to rewrite it a bit, to make the classes nested.
That is, there is .container> .rect markup for which there are styles

.container
    ...
.rect
    ...

I rewrite as in the code below, but the code stops working -

.container
    ...
    .rect
        ...

.container
    ...
.container .rect
    ...

I thought that template engines break the sequence, but I checked it in the browser itself and it can be seen that the nesting of html elements is correct. I tried to recreate on a thumbnail, but the error disappears and everything works. Does anyone have any ideas for this case?

Answer 1

CSS
SCSS

.container {
    > .rect {}
}