Hello,
i am using Chrome version 73 and the Adobe Experience Cloud Debugger version 0.0.812 and I am able to see the Target/at.js calls in the debugger. You can go into your extension settings in Chrome to update to the current release version of the debugger if you are not on the current release. I do know there were some issues with version 0.0.811 that affected at.js 2.0.
If you are on the current release version of the debugger and are still having trouble, please file an incident with steps to replicate what you are seeing (IE, what is your Target account info, what Target activity, and what URL you are going to) and Customer Care can research this further.
Thanks,
Peter Hartung
Technical Support Consultant
Customer Experience
Adobe