Webnus

If you do not want the loading page to appear in full screen, but instead you want these changes to appears on MEC current shortcode, what should I do?

All you need to do is to put the following CSS code in the MEC Settings > Custom CSS: 

.mec-wrap {
    overflow: hidden;
    position: relative;
}
.mec-modal-preloader,
.mec-month-navigator-loading {
    position: absolute;
}