It seems that we might be discussing two completely different problems here.
The first report was about "nothing happens" after starting Arduino Create Agent:
The expected visible effect of starting Arduino Create Agent is that an Arduino logo icon will appear on the macOS "menu bar". The other effect is that Arduino Cloud will then recognize that Arduino Create Agent is running and also be able to recognize the Arduino boards you have connected to your computer.
I didn't ever receive an answer to my question about whether the icon was present in the menu bar or not, so I have no understanding of the exact nature of that problem.
I did see another topic where users are reporting the problem of the icon not appearing after launching:
The second report was about Arduino Create Agent launching as expected (as indicated by the black icon in the menu bar, but that Arduino Cloud did not recognize Arduino Create Agent:
This problem is caused by certain security restrictions of the browser (this is why people are experiencing it on Safari but not Chrome browser) blocking the communication between Arduino Cloud and Arduino Create Agent.
There is a simple solution to this problem. @geoffhall777 was already kind enough to share it with us, but in case it will be useful I'll provide more detailed instructions that the affected users can follow:
Generate and Install HTTPS certificates
- Control-click on the Arduino Create Agent icon on the macOS "menu bar".
A menu will open. - Select Generate and Install HTTPS certificates from the menu.
A "You are making changes to your Certificate Trust Settings" dialog will open. - Enter your macOS user password in the "You are making changes to your Certificate Trust Settings" dialog.
- Click the "Update Settings" button.
After doing that, you should find that Arduino Cloud is able recognize that Arduino Create Agent is running and recognizes the Arduino boards you have connected to your computer, even when using the Safari browser.
Please let me know if you have any questions or problems while following those instructions.