airdrop iOS->osx ceased to work in simple mode

The moment firewalla was introduced, airdrop (which has its own issues) ceased to work but only in one direction. From IOS to OSX.

Tried:

*upgrading to IOS 14.x

*trying all recommended things associated (since it was working reliably didn't think they were an issue anyway)

apparently airdrop needs IGMP snooping and multicast? not 100% sure. Neither OSX nor IOS has any special firewalla rules attached.