Hello @Gino23,
A few things to check.
Do the reservation requests appear on your calendar? If they're valid requests the dates will show, in orange I think, as pending.
Do the emails have "express@airbnb.com" on the "From" line? If not then they're most likely not from Airbnb. How do I know if an email is really from Airbnb?
Check your "push" notification settings. How do I update my notification settings?
If the dates appear as pending, the email appears valid and your push notification settings are correct then you'll have to contact Airbnb customer service.
Steve.