guest that airbnb did not send him review notification

[Al-Shaimaa0]

so I had a guest in one of my experiences in Airbnb and he asked me why Airbnb did not send him notification either by email or on his Airbnb application so i contacted Airbnb and they told me that the guests munt look for it in his notification bar and I contacted my guest and told him that so he send me screenshots from his account that indicates that really Airbnb did not send him the notification  

I contacted again Airbnb and no answer that was 10 days ago and I am afraid that the expire date for him to give me a review is near 

anyone here can help me?