I managed to solve the issue. The problem was due to hiding the overlay container:

styles.scss

.cdk-overlay-container {
    display: none !important;
}

After removing that, the options were displayed.

I added the display: none in the first place because the overlay containers used to be positioned wrongly before adding the paginator, but this solved the position issue:

styles.scss

@use '@angular/material' as mat;
@include mat.core();