Airdrop not working via wifi
I have a macbook, iPad and iPhone and airdrop works perfectly using cellular data. However, when these devices are connected via my home wifi, airdrop stops working. It seems that something is either incorrectly set up on my router or there are some ports blocked which airdrop requires to work. Airplay and internet and everything else works fine via the router - just not airdrop.
any ideas?
iPad, iOS 9.3.2