I bought an iMac 2020 yesterday and all's fine except I can't airdrop to it from iPhone or iPad. The iPhone and iPad see the iMac but it just times out. Strangely I can airdrop from the iMac just not to it. Really annoying as I use airdrop a lot with photos to keep all devices in sync. Its turned on in finder(everyone). I have used airdrop to my MacBook Pro for many years so I just don't understand what is wrong. Any help would be appreciated. Thanks