Unable to transfer from iPhone to iMac using AirDrop after installing latest security updates

Has anyone had this problem after installing the latest security updates on iPhone 15 Plus and recent iMac 24 Inch? I am now unable to transfer photos or video from iPhone to iMac using AirDrop. The iMac is requesting an Airdrop passcode (6 digits) from the iPhone. The iPhone does not recognise the passcode. Until the latest updates (IOS26.6.1 and Tahoe 26.6.2) were installed I was able to use Airdrop without the need for a passcode. I have checked some potential issues (such as setting to everyone for 10 minutes on AirDrop, network settings), but still unable to transfer anything. Any other ideas? Is it a software issue?