Not able to iterate through method calls and create a comprehensive sequence diagram

[apattath]

It tries to search for methods called only within the given file, but not in the entire code repo in VS. This feels different from normal github copilot where it's able to search across all files.
I keep getting errors like below:

wasn't able to find specific symbol information through the search, but I have access to the full code for the EmailController. Let me analyze the SendMailAsync method and trace through all its dependencies to create a comprehensive sequence diagram.