It is no longer possible to click anything on the page once a modal is opened. You can only dismiss it by pressing Escape. This seems to be the case with all current versions of CoreUI, not just Angular. Even the documentation page for modals has this problem. Click the "Launch demo modal" button on the above page and try to click anything.

The issue is with this recent addition to the theme's core/_temp.scss:

.modal-open .modal {
  display: block;
}

Not sure why this was even added, but this causes all modals defined on the page to have display: block; when any one modal is open. This means only the last modal defined on the page would be interactive.

Temporary workaround - add the following to your _custom.css:

// Fix for error in CoreUI
.modal-open {
  .modal {
    display: none !important;
  }
  .modal.show {
    display: block !important;
  }
}