Hi,

Please go to Appearance → Customize → Custom CSS then add the following custom CSS code:

.navigation .menu li.penci-block-mega.penci-megapos-flexible.menu-item-91 {
  position: static !important;;
}
.navigation .menu li.penci-block-mega.penci-megapos-flexible.menu-item-91 .penci-mega-full-width {
  left: 0 !important;;
  right: 0 !important;
}
.navigation .menu li.penci-block-mega.penci-megapos-flexible.menu-item-91 .penci-mega-full-width .container {
  width: 100%;
}

Regards,
PenciDesign.