Contacts malfunction using BigSur7.4 on MacBook pro

Hey there Bill R,

While your Mac is close to being nine years old, it is something to consider regarding being compatible with the latest security updates, compatibility with newer devices/software, etc. That being said, we'd like to help by learning more about what's happening, along with ruling out some possible causes to the issues you described:

1. When did the issues within Contacts start to occur?
2. As a full, or nearly full internal storage could cause the issues you described, how much internal storage is available in your Mac? You can check by clicking the Apple logo near the top left, then on About This Mac > Storage.
3. Sometimes unexpected behavior can be resolved with a restart. Check out the section ‘Restart your Mac' here: Shut down or restart your Mac
4. You mentioned that the issue occurred while in safe mode, but what occurs if you test it within a new user? To test for this in a new user, check out the steps under 'Add account' here: Set up users, guests, and groups on Mac
5. While we understand this is occurring only within Contacts, we still recommend taking the remaining steps from this link to help rule out some other possible causes to these issues occurring: If your Mac runs slowly

Cheers!