Sometime window non-modal doesn't popup

Problem/Motivation

As i said in the title... not sure why. doesn't popup any error and defaults to the drupal success thing at the top of the page.

however if I had css:

.messages__wrapper {
    position: fixed;
    right: 10px;
    top: 10%;
    z-index: 999;
}

I get the same effect, but might afect all messages in drupal