Badiashile is in the right position in that still you showed, but Disasi (RB), who you've absolved from any criticism, is at left back, and has left a huge hole on his side where the 5 Gent players are ! Veiga is also well out of position for a left back, seeing as he's popping up between the two centre backs, which helps allow the cross.
Perhaps they are collectively confused by the set piece positioning they are instructed to take up from the preceding corner kick, as per whatever the new set piece guy is telling them ? certainly very slow to get back into "normal" shape afterwards ...